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Photo: Wilstone Reservoir from the Wendover Arm of the Grand Union Canal - geograph.org.uk - 1252514 by Chris Reynolds (CC BY-SA 2.0) License
Union Reservoir
Lake · Longmont, Colorado
Cool today
Things to Do Near Union Reservoir
Top-rated tours and experiences around Longmont, powered by Viator — free cancellation on most.
Rocky Mountain 6-Zipline Adventure on CO Longest and Fastest!
★ 5.0(799)
from $130
Rocky Mountain 4-Zipline Adventure on CO Longest and Fastest!
★ 5.0(31)
from $110
Mount Blue Sky, Clear Creek Canyon & Red Rocks Park (Mount Evans)
★ 4.7(65)
from $149
Ride the Heber Valley 1899 Railroad and see Deer Creek Reservoir
★ 4.2(49)
from $125
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Weather at Union Reservoir
47°F, Clear · H 74° / L 44° · 2% chance of rain3-day forecast
H: 74° L: 44°
Clear
47°
|
Feels like 44°
Precipitation
2%
Humidity
50%
Wind
5 mph
UV Index
0
12 AM
48°
3 AM
47°
6 AM
44°
9 AM
56°
12 PM
69°
3 PM
74°
6 PM
64°
9 PM
55°
Frequently asked questions
- Where is Union Reservoir?
- Union Reservoir is a lake in Longmont, Colorado.
- Can you swim at Union Reservoir?
- There is no fixed answer for Union Reservoir: whether it is safe to swim there on a given day depends on the water temperature, recent rainfall, and any advisories posted at Union Reservoir in Longmont, Colorado. Check current water conditions before you go, and follow posted signs and local guidance.
- How is Union Reservoir rated?
- Union Reservoir in Longmont, Colorado has an average visitor rating of 4.3 out of 5, based on 199 reviews.
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Location & Contact
Longmont, CO 80504
Longmont, Colorado 80504
🏞️ Best times & visiting tips
- ›Check for boat launch facilities and fees
- ›Obtain required fishing licenses before arrival
- ›Be aware of lake-specific regulations and restrictions
- ›Monitor water quality reports before swimming
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