Longmont weather in August: Longmont, Colorado: normal highs, lows, rain and records for August
Longmont in August has a normal high of 88°F and a normal low of 54°F, a daily mean of 71°F, falling from 90°F on the 1st to 85°F by the 31st. Measurable precipitation falls on 7 days in a normal August, 1.95 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 31°C and low of 12°C, 50 mm of precipitation in August.
- NOAA stationLongmont (2 mi ESE)
- Station IDUSC00055116
- Location40.17°N 105.08°W
- Elevation4,950 ft (1,509 m)
- From the center1 miles
- Population99,818
- Jan 45° 14°
- Feb 47° 17°
- Mar 57° 26°
- Apr 63° 32°
- May 73° 41°
- Jun 84° 51°
- Jul 91° 55°
- Aug 88° 54°
- Sep 80° 46°
- Oct 66° 33°
- Nov 54° 24°
- Dec 45° 15°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Longmont in August?
The normal high is 88°F and the normal low 54°F, for a daily mean of 70.8°F. August is 2.3°F cooler than July and 7.8°F warmer than September. August is the 2nd warmest month of the year in Longmont and the 3rd wettest. Across the month the normal high falls 5°F, from 90°F on August 1 to 85°F on August 31. From one year to the next August's mean temperature typically moves about 2.1°F either way (NOAA's standard deviation), so roughly two Augusts in three average between 69°F and 73°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 24%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| August 1 | 90°F | 56°F | 24% | 12% |
| August 8 | 89°F | 55°F | 24% | 12% |
| August 15 | 88°F | 54°F | 23% | 11% |
| August 22 | 87°F | 53°F | 22% | 11% |
| August 31 | 85°F | 51°F | 21% | 11% |
Every day of August: normal high, low and chance of precipitation (warmest afternoon August 1, coldest night August 31)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| August 1 | 90°F | 56°F | 24% | 12% | 14 h 20 min |
| August 2 | 90°F | 55°F | 24% | 12% | 14 h 20 min |
| August 3 | 90°F | 55°F | 24% | 12% | 14 h 10 min |
| August 4 | 90°F | 55°F | 24% | 12% | 14 h 10 min |
| August 5 | 90°F | 55°F | 24% | 12% | 14 h 10 min |
| August 6 | 89°F | 55°F | 24% | 12% | 14 h 10 min |
| August 7 | 89°F | 55°F | 24% | 12% | 14 h 10 min |
| August 8 | 89°F | 55°F | 24% | 12% | 14 h |
| August 9 | 89°F | 55°F | 24% | 12% | 14 h |
| August 10 | 89°F | 55°F | 24% | 12% | 14 h |
| August 11 | 89°F | 55°F | 24% | 12% | 14 h |
| August 12 | 88°F | 54°F | 24% | 12% | 14 h |
| August 13 | 88°F | 54°F | 23% | 11% | 13 h 50 min |
| August 14 | 88°F | 54°F | 23% | 11% | 13 h 50 min |
| August 15 | 88°F | 54°F | 23% | 11% | 13 h 50 min |
| August 16 | 88°F | 54°F | 23% | 11% | 13 h 50 min |
| August 17 | 88°F | 54°F | 23% | 11% | 13 h 40 min |
| August 18 | 88°F | 54°F | 23% | 11% | 13 h 40 min |
| August 19 | 87°F | 54°F | 23% | 11% | 13 h 40 min |
| August 20 | 87°F | 53°F | 23% | 11% | 13 h 40 min |
| August 21 | 87°F | 53°F | 22% | 11% | 13 h 30 min |
| August 22 | 87°F | 53°F | 22% | 11% | 13 h 30 min |
| August 23 | 87°F | 53°F | 22% | 11% | 13 h 30 min |
| August 24 | 87°F | 53°F | 22% | 11% | 13 h 30 min |
| August 25 | 86°F | 53°F | 22% | 11% | 13 h 20 min |
| August 26 | 86°F | 52°F | 22% | 11% | 13 h 20 min |
| August 27 | 86°F | 52°F | 22% | 11% | 13 h 20 min |
| August 28 | 86°F | 52°F | 22% | 11% | 13 h 20 min |
| August 29 | 86°F | 52°F | 21% | 11% | 13 h 10 min |
| August 30 | 86°F | 52°F | 21% | 11% | 13 h 10 min |
| August 31 | 85°F | 51°F | 21% | 11% | 13 h 10 min |
- Normal high
- 88°FAugust average
- Normal low
- 54°FAugust average
- Precipitation
- 1.95 inmonth total
- Days with precipitation
- 70.01 inch or more
- Days at 90°F or more
- 15
- Daylight
- 14 h 20 min to 13 h 10 minAugust 1 to August 31
- Days at 70°F or more
- 30
- Days at 80°F or more
- 27
- Sunshine
- 76%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00055116; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Longmont in August?
On a given August day the chance of 0.01 inch or more is 23% on average, highest around August 4 (24%). In all, 1.95 in falls on 7 days of a normal August, 1 of them with an inch or more.
In a normal August in Longmont, 15 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00055116.
What are the records for August in Longmont?
The warmest August temperature on this station's record (since 1893) is 104°F, on August 8, 1995; the coldest is 37°F, on August 27, 1992. The wettest August brought 4.77 in (1992).
The August mean against the 1991-2020 normal of 70.8°F: 2021 72.2°F (+1.4), 2022 74.1°F (+3.3), 2023 71.6°F (+0.8), 2024 73.6°F (+2.8), 2025 72.3°F (+1.5), 2026 75.4°F (+4.6). 6 of 6 ran warmer than normal.
| August | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 72.2°F | +1.4°F | 1.27 in |
| 2022 | 74.1°F | +3.3°F | 2.04 in |
| 2023 | 71.6°F | +0.8°F | 2.13 in |
| 2024 | 73.6°F | +2.8°F | 0.74 in |
| 2025 | 72.3°F | +1.5°F | 1.10 in |
| 2026 | 75.4°F | +4.6°F | 0.58 in |
Source: records: ACIS, station USC00055116; recent months: ACIS, station USC00055116. Records and recent months use complete months only.
How does August in Longmont compare across Colorado?
Across the 125 places PlainClimate covers in Colorado, August normal highs run from 68°F in Leadville to 93°F in Lamar; Longmont's is 88°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.