Historical Weather in Longmont, CO
See 55+ years of weather history for any date in Longmont going back to 1970.
Part of Colorado weather history · Colorado temperature records
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Today in Longmont Weather HistorySee records, averages, and 55+ years of data for today's date
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Monthly Climate Averages
Historical temperature and precipitation averages for Longmont, CO, based on 55+ years of weather data.
Warmest MonthJulyAvg High: 88°F / Low: 57°F
Coldest MonthJanuaryAvg High: 44°F / Low: 18°F
Jan
44°/ 18°
💧 3.3"
❄️ 2.1"
Feb
47°/ 20°
💧 3.5"
❄️ 2.1"
Mar
55°/ 28°
💧 6.1"
❄️ 2.6"
Apr
63°/ 34°
💧 7.3"
❄️ 2.9"
May
71°/ 43°
💧 6.7"
❄️ 2.6"
Jun
83°/ 52°
💧 5.4"
Jul
88°/ 57°
💧 4.3"
Aug
87°/ 56°
💧 4.2"
Sep
79°/ 47°
💧 5.9"
❄️ 3.1"
Oct
66°/ 36°
💧 5.0"
❄️ 2.8"
Nov
53°/ 26°
💧 5.0"
❄️ 2.7"
Dec
46°/ 20°
💧 4.0"
❄️ 2.5"
Temperatures in Fahrenheit. Precipitation and snowfall in inches.
Longmont, CO Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
Avg high Avg low
Longmont, CO Monthly Precipitation
Average rainfall and snowfall per month, in inches.
Rain (in) Snow (in)
Longmont, CO Daily Temperature Calendar
Average daily high temperature for every day of the year. Each cell is the climatological mean for that calendar day across 55 years of NOAA data.
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Best Time to Visit Longmont, CO
Longmont, CO has no months that meet our "pleasant" threshold — every season has tradeoffs.
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Pleasant (65-82°F, ≤2.5" rain) Mild Less ideal
Longmont Temperature Records
- Record High: The hottest temperature ever recorded in Longmont, CO is 106°F, set on July 7, 1973.
- Record Low: The coldest temperature ever recorded in Longmont, CO is -31°F, set on December 22, 1990.
- Data Coverage: Based on 57 years of data from NOAA weather station: LONGMONT 2 ESE.
All-Time Record High
106°F
July 7, 1973
All-Time Record Low
-31°F
December 22, 1990
Monthly Temperature Records in Longmont
| Month | Record High | Record Low |
|---|---|---|
| January | 75°F(1982) | -30°F(1984) |
| February | 77°F(1982) | -28°F(1989) |
| March | 85°F(1997) | -14°F(1989) |
| April | 91°F(2022) | -7°F(1975) |
| May | 100°F(2003) | 10°F(2013) |
| June | 106°F(1994) | 18°F(2014) |
| July | 106°F(1973) | 35°F(2024) |
| August | 104°F(1995) | 37°F(1992) |
| September | 103°F(2019) | 15°F(1985) |
| October | 90°F(1980) | -8°F(2020) |
| November | 82°F(2025) | -16°F(1993) |
| December | 77°F(2025) | -31°F(1990) |
Longmont Snow RecordsSee the top 10 snowiest days ever recorded
→National Parks in Colorado
Holiday Weather in Longmont
Weather Analysis & Trends
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