Question 1

What is the current water temperature at Union Reservoir?

Accepted Answer

The current water temperature at Union Reservoir is 66°F as of March 1, 1786. This temperature reading is based on our advanced satellite monitoring system and current data collection. Water temperature is a crucial factor for fishing success and water activities.

Question 2

How often is the Union Reservoir water temperature updated?

Accepted Answer

Water temperature data for Union Reservoir is updated daily through our satellite monitoring system. The last update was made on March 1, 1786. We use advanced thermal imaging and surface monitoring technology to provide accurate temperature readings.

Question 3

What activities are suitable for the current water temperature at Union Reservoir?

Accepted Answer

With the current water temperature of 66°F at Union Reservoir, conditions are ideal for fishing, boating, and moderate water activities. The temperature typically fluctuates 2-3 degrees throughout the day. This data is monitored via satellite and updated regularly to help you plan your lake activities.

Question 4

How good is the fishing at Union Reservoir with the current water temperature?

Accepted Answer

The current water temperature of 66°F at Union Reservoir is ideal for catching Largemouth bass, Smallmouth bass, Black crappie, Yellow perch, Northern pike. These species are typically most active at this temperature range. For best results, fish during early morning or late evening hours when fish are most active. Always check local fishing regulations and licenses before fishing.

Question 5

What is Union Reservoir and what activities are available?

Accepted Answer

Union Reservoir is a natural body of water located in Weld County, Colorado, covering an area of 736 acres. Originally known as Calkins Lake, the reservoir was formed during the last glacial age and is one of the few natural lakes in Colorado. The lake is a popular destination for outdoor enthusiasts, offering a range of recreational activities, including fishing, boating, camping, and hiking.

The Union Ditch Company played a significant role in shaping the lake's history. In 1903, the company began drilling a tunnel to release water into the St. Vrain Creek, which was crucial for agricultural purposes. The water released into the creek made Union Reservoir a true reservoir under Colorado water law. The reservoir was then used as a water storage facility for agricultural irrigation and municipal purposes.

Fishing is a popular activity on Union Reservoir, with the lake being home to several fish species, including bluegill, catfish, crappie, largemouth bass, and walleye. The lake's large size provides plenty of space for anglers to explore and find their perfect fishing spot. The lake is stocked with fish regularly, making it a great place for both novice and experienced anglers to catch a big one.

Boating is another popular activity on Union Reservoir, with motorized boats allowed on the lake. The lake's size and calm waters provide an excellent environment for water sports such as water skiing, wakeboarding, and tubing. The lake has several boat launches and docks, making it easy for boaters to access the water. Kayaking and paddleboarding are also popular ways to explore the lake's serene waters.

The Union Reservoir offers several camping options, with both primitive and developed campsites available. The developed campsites offer several amenities, including electricity, water, and picnic tables. The primitive campsites offer a more secluded camping experience, with no amenities available.

The lake is also surrounded by several hiking trails, providing an excellent opportunity for hikers and nature enthusiasts to explore the area's beautiful scenery. The trails offer stunning views of the lake and surrounding wilderness, making it an ideal place for a peaceful nature walk. The lake's proximity to several nature reserves and wildlife areas also makes it an excellent destination for birdwatchers and wildlife enthusiasts.

In conclusion, Union Reservoir is a natural body of water with a rich history and a wide range of outdoor recreational activities available. The lake's large size and diverse fish population make it an ideal destination for fishing enthusiasts, while its calm waters provide an excellent environment for boating and water sports. The lake's surrounding campsites and hiking trails offer a perfect opportunity for visitors to experience Colorado's natural beauty and wildlife. Union Reservoir is a popular destination for outdoor enthusiasts of all ages and interests.

Question 6

How big and deep is Union Reservoir?

Accepted Answer

Union Reservoir is a substantial body of water covering 736.00 acres (1.15 square miles) with a maximum depth of 0.00 meters (0 feet). This size and depth make it ideal for various activities including and water recreation.

Question 7

What are the current conditions at Union Reservoir?

Accepted Answer

Current conditions at Union Reservoir as of May 24, 2026:
      Water temperature is 66°F, 
      weather is MostlyClear, 
      and water clarity is typical for the season. 
      These conditions are regularly updated to help you plan your visit.

Question 8

When is the best time to fish at Union Reservoir?

Accepted Answer

The best fishing times at Union Reservoir vary by season:
      Spring (March-May): Spring fishing at the lake is excellent for Largemouth bass, Smallmouth bass, Bluegill, Channel catfish, Black crappie, Yellow perch, Rainbow trout, Brown trout, Northern pike. Focus on shallow areas warming up first, and use light tackle as fish become more active after winter.
      Summer (June-August): During summer months, fish are most active early morning and late evening. Look for Largemouth bass, Smallmouth bass, Bluegill, Channel catfish, Black crappie, Yellow perch, Rainbow trout, Brown trout, Northern pike in deeper, cooler waters during mid-day.
      Fall (September-November): Fall brings excellent fishing opportunities as Largemouth bass, Smallmouth bass, Bluegill, Channel catfish, Black crappie, Yellow perch, Rainbow trout, Brown trout, Northern pike feed heavily before winter. Focus on areas with falling water temperatures.
      Winter (December-February): Ice fishing is popular during winter months. Target Largemouth bass, Smallmouth bass, Bluegill, Channel catfish, Black crappie, Yellow perch, Rainbow trout, Brown trout, Northern pike in shallower bays and near structure, always ensuring safe ice conditions.
      Additionally, early morning and late evening typically offer the best fishing conditions.

Question 9

What facilities and access points are available at Union Reservoir?

Accepted Answer

Union Reservoir offers the following facilities and amenities:

Please note that some facilities may have seasonal hours or closures. Check current conditions and regulations before your visit.

Question 10

What types of fish can I catch at Union Reservoir?

Accepted Answer

Union Reservoir is home to Largemouth bass, Smallmouth bass, Bluegill, Channel catfish, Black crappie, Yellow perch, Rainbow trout, Brown trout, Northern pike. Each species has specific patterns and preferences that can help you plan your fishing trip effectively.

Question 11

What are the best techniques and times to catch Largemouth bass at Union Reservoir?

Accepted Answer

For Largemouth bass at Union Reservoir:
- Best seasons: Spring, Fall
- Active times: Dawn, Dusk
- Preferred water temperature: 65-80°F
- Typical depth: Shallow in spring/fall, deeper in summer
- Habitat: Lakes, Ponds, Rivers, Reservoirs
- Spawning season: Late Spring

Recommended techniques:
- Fishing methods: Pitching and flipping, Trolling, Casting
- Effective lures: Plastic worms, Crankbaits, Spinnerbaits
- Natural bait options: Shiners, Frogs, Worms

Tackle recommendations:
- Rod: Medium-heavy power rod
- Reel: Baitcasting reel
- Line: 10-20 lb test

Question 12

What are the best techniques and times to catch Smallmouth bass at Union Reservoir?

Accepted Answer

For Smallmouth bass at Union Reservoir:
- Best seasons: Spring, Fall
- Active times: Morning, Late Afternoon
- Preferred water temperature: 65-75°F
- Typical depth: Shallow in spring/fall, deeper in summer
- Habitat: Streams, Rivers, Lakes, Reservoirs
- Spawning season: Spring

Recommended techniques:
- Fishing methods: Drop shotting, Jigging, Casting
- Effective lures: Jigs, Tube baits, Soft plastics
- Natural bait options: Crayfish, Minnows, Worms

Tackle recommendations:
- Rod: Medium power rod
- Reel: Spinning reel
- Line: 6-15 lb test

Question 13

What are the best techniques and times to catch Bluegill at Union Reservoir?

Accepted Answer

For Bluegill at Union Reservoir:
- Best seasons: Spring, Summer
- Active times: Morning, Afternoon
- Preferred water temperature: 69-75°F
- Typical depth: 1-10 feet in spring, 10-20 feet in summer
- Habitat: Lakes, Ponds, Streams
- Spawning season: Late Spring to Early Summer

Recommended techniques:
- Fishing methods: Bobber fishing, Casting
- Effective lures: Small jigs, Spinnerbaits
- Natural bait options: Worms, Crickets

Tackle recommendations:
- Rod: Ultralight power rod
- Reel: Spinning reel
- Line: 2-6 lb test

Question 14

What are the best techniques and times to catch Channel catfish at Union Reservoir?

Accepted Answer

For Channel catfish at Union Reservoir:
- Best seasons: Spring, Summer
- Active times: Night
- Preferred water temperature: 70-85°F
- Typical depth: 5-15 feet in spring, 15-30 feet in summer
- Habitat: Lakes, Rivers, Ponds
- Spawning season: Late Spring to Early Summer

Recommended techniques:
- Fishing methods: Bottom fishing
- Effective lures: None commonly used
- Natural bait options: Cut bait, Stink bait, Liver

Tackle recommendations:
- Rod: Medium-heavy to heavy power rod
- Reel: Baitcasting reel
- Line: 10-30 lb test

Question 15

What are the best techniques and times to catch Black crappie at Union Reservoir?

Accepted Answer

For Black crappie at Union Reservoir:
- Best seasons: Spring, Fall
- Active times: Morning, Evening
- Preferred water temperature: 58-68°F
- Typical depth: Shallow in spring, deeper in summer
- Habitat: Lakes, Ponds, Slow-moving rivers
- Spawning season: Spring

Recommended techniques:
- Fishing methods: Vertical jigging, Casting, Bobber fishing
- Effective lures: Small jigs, Soft plastics
- Natural bait options: Minnows, Worms

Tackle recommendations:
- Rod: Light power rod
- Reel: Spinning reel
- Line: 2-6 lb test

Question 16

What are the best techniques and times to catch Yellow perch at Union Reservoir?

Accepted Answer

For Yellow perch at Union Reservoir:
- Best seasons: Spring, Winter
- Active times: Morning, Afternoon
- Preferred water temperature: 50-68°F
- Typical depth: 3-12 feet in spring, 10-25 feet in summer
- Habitat: Lakes, Rivers, Ponds
- Spawning season: Spring

Recommended techniques:
- Fishing methods: Vertical jigging, Bobber fishing
- Effective lures: Small jigs, Spoons, Spinnerbaits
- Natural bait options: Minnows, Worms

Tackle recommendations:
- Rod: Ultralight to light power rod
- Reel: Spinning reel
- Line: 2-6 lb test

Question 17

What are the best techniques and times to catch Rainbow trout at Union Reservoir?

Accepted Answer

For Rainbow trout at Union Reservoir:
- Best seasons: Spring, Fall
- Active times: Morning, Late afternoon
- Preferred water temperature: 50-60°F
- Typical depth: 3-9 feet in spring, deeper in summer
- Habitat: Streams, Rivers, Lakes
- Spawning season: Spring

Recommended techniques:
- Fishing methods: Fly fishing, Spincasting
- Effective lures: Small spinners, Spoons, Fly patterns
- Natural bait options: Worms, Salmon eggs, Insects

Tackle recommendations:
- Rod: Ultralight to light power rod
- Reel: Spinning or fly reel
- Line: 2-6 lb test

Question 18

What are the best techniques and times to catch Brown trout at Union Reservoir?

Accepted Answer

For Brown trout at Union Reservoir:
- Best seasons: Spring, Fall
- Active times: Dawn, Dusk, Night
- Preferred water temperature: 50-65°F
- Typical depth: 2-10 feet in streams, deeper in lakes
- Habitat: Streams, Rivers, Lakes
- Spawning season: Fall

Recommended techniques:
- Fishing methods: Fly fishing, Spincasting, Trolling in lakes
- Effective lures: Streamers, Spoons, Spinners
- Natural bait options: Worms, Crickets, Grasshoppers

Tackle recommendations:
- Rod: Light to medium power rod
- Reel: Spinning or fly reel
- Line: 4-8 lb test

Question 19

What are the best techniques and times to catch Northern pike at Union Reservoir?

Accepted Answer

For Northern pike at Union Reservoir:
- Best seasons: Spring, Fall
- Active times: Morning, Afternoon
- Preferred water temperature: 55-70°F
- Typical depth: 3-12 feet in spring, 10-25 feet in summer
- Habitat: Lakes, Rivers, Marshes
- Spawning season: Early Spring

Recommended techniques:
- Fishing methods: Casting, Trolling
- Effective lures: Spoons, Spinners, Swimbaits
- Natural bait options: Live fish

Tackle recommendations:
- Rod: Medium-heavy to heavy rod
- Reel: Spinning or baitcasting reel
- Line: 20-40 lb test

Question 20

What are the best fishing seasons at Union Reservoir?

Accepted Answer

Spring: Best for catching Largemouth bass, Smallmouth bass, Bluegill, Channel catfish, Black crappie, Yellow perch, Rainbow trout, Brown trout, Northern pike

Fall: Best for catching Largemouth bass, Smallmouth bass, Black crappie, Rainbow trout, Brown trout, Northern pike

Summer: Best for catching Bluegill, Channel catfish

Winter: Best for catching Yellow perch

Question 21

What water recreation activities are available at Union Reservoir?

Accepted Answer

Union Reservoir offers various recreational opportunities including:
      - Fishing

Additional lake information:
      - Lake size: 736.00 acres (1.15 square miles)
      - Maximum depth: 0.00 meters

The lake is particularly suitable for fishing and boating 
      during current conditions. Always check weather forecasts and local regulations before activities.

Question 22

What's the best time to visit Union Reservoir, and how's the weather?

Accepted Answer

The best time to visit Union Reservoir depends on your planned activities:
      - Summer (June-August): Ideal for swimming, boating, and water sports
      - Spring/Fall: Excellent fishing and fewer crowds
      - Winter: Ice fishing when conditions permit
      Current weather is MostlyClear. 
      Check our current updates for water temperature and conditions before your visit.

Question 23

What permits and regulations should I know about for Union Reservoir?

Accepted Answer

For Union Reservoir, you should be aware of:
      - Fishing license requirements (check state regulations)
      - Boat registration requirements

For specific requirements and current regulations:
      
      - Contact local authorities
      - Visit the DNR website
      - Visit official websites listed below

Question 24

Where can I find more information about Union Reservoir?

Accepted Answer

You can find detailed information about Union Reservoir through these official resources:
        
        - Additional Information
        
        These resources provide up-to-date information about:
        
        - Current lake conditions
        - Facility hours and availability
        - Special notices and alerts
        
        - Seasonal updates and events
        
        Official websites: https://www.longmontcolorado.gov/Home/Components/FacilityDirectory/FacilityDirectory/4/708

Question 25

What is the water temperature at Union Reservoir in January?

Accepted Answer

In January, the water temperature at Union Reservoir is approximately 35.00°F. 
        This information helps in planning activities like water activities.

Question 26

What is the water temperature at Union Reservoir in February?

Accepted Answer

In February, the water temperature at Union Reservoir is approximately 35.00°F. 
        This information helps in planning activities like water activities.

Question 27

What is the water temperature at Union Reservoir in March?

Accepted Answer

In March, the water temperature at Union Reservoir is approximately 37.07°F. 
        This information helps in planning activities like water activities.

Question 28

What is the water temperature at Union Reservoir in April?

Accepted Answer

In April, the water temperature at Union Reservoir is approximately 53.93°F. 
        This information helps in planning activities like water activities.

Question 29

What is the water temperature at Union Reservoir in May?

Accepted Answer

In May, the water temperature at Union Reservoir is approximately 58.43°F. 
        This information helps in planning activities like water activities.

Question 30

What is the water temperature at Union Reservoir in June?

Accepted Answer

In June, the water temperature at Union Reservoir is approximately 68.36°F. 
        This information helps in planning activities like water activities.

Question 31

What is the water temperature at Union Reservoir in July?

Accepted Answer

In July, the water temperature at Union Reservoir is approximately 75.00°F. 
        This information helps in planning activities like water activities.

Question 32

What is the water temperature at Union Reservoir in August?

Accepted Answer

In August, the water temperature at Union Reservoir is approximately 76.14°F. 
        This information helps in planning activities like water activities.

Question 33

What is the water temperature at Union Reservoir in September?

Accepted Answer

In September, the water temperature at Union Reservoir is approximately 73.43°F. 
        This information helps in planning activities like water activities.

Question 34

What is the water temperature at Union Reservoir in October?

Accepted Answer

In October, the water temperature at Union Reservoir is approximately 58.50°F. 
        This information helps in planning activities like water activities.

Question 35

What is the water temperature at Union Reservoir in November?

Accepted Answer

In November, the water temperature at Union Reservoir is approximately 49.36°F. 
        This information helps in planning activities like water activities.

Question 36

What is the water temperature at Union Reservoir in December?

Accepted Answer

In December, the water temperature at Union Reservoir is approximately 34.71°F. 
        This information helps in planning activities like water activities.

Question 37

What are the current fishing conditions at Union Reservoir?

Accepted Answer

Current water temperature at Union Reservoir is 66°F. 
        These conditions are ideal for catching Largemouth bass, Smallmouth bass, Black crappie, Yellow perch, Northern pike.

Question 38

What is the maximum depth of Union Reservoir?

Accepted Answer

Union Reservoir has a maximum depth of 0.00 meters (0 feet). This depth provides excellent habitat for various fish species and supports diverse aquatic life. The lake's depth profile makes it suitable for both shallow-water fishing and deep-water activities.

Question 39

How big is Union Reservoir?

Accepted Answer

Union Reservoir covers an area of 736.00 acres (1.15 square miles) at full pool. The lake is currently holding 667.23 acres of water, which represents 90.7% of its total capacity. This substantial size makes it an important recreational resource for Weld County, offering extensive opportunities for fishing, boating, and other water activities.

Question 40

Where is Union Reservoir located?

Accepted Answer

Union Reservoir is located in Longmont, Weld County, CO. The lake is accessible to the public and serves as a popular destination for outdoor activities. Its location in Weld County makes it easily accessible from Longmont and surrounding communities.

Question 41

What is the current water level at Union Reservoir?

Accepted Answer

Union Reservoir is currently holding 667.23 acres of water, compared to its full capacity of 736.00 acres. This represents 90.7% of its total capacity. The lake is at a healthy level, ideal for all water activities. These water levels are monitored regularly and impact various recreational activities on the lake.

Union Reservoir

Union Reservoir

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Union Reservoir

Union Reservoir

Ask what to do at Union Reservoir today.

Active-water pattern for Largemouth bass / Smallmouth bass

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Weather Forecast

Hourly Wind Forecast

24

Daily Pressure Forecast

About Union Reservoir