Climate averages 1991–2020
Longmont weather
in October.
A mild, moderately wet month: the 6th warmest and the 7th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
October is a mild month in Longmont: daytime highs average 16.8°C and nights cool to about 3.2°C. By daytime temperature it is the 6th warmest of the 12 months.
Expect about 41 mm of rain on roughly 7 days, which makes October a moderately wet month (the 7th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 11 h 11 min on an average October day.
The nearest other city in this atlas is Boulder (22 km away). In October its highs average 16.5°C, about as warm as Longmont, with 48 mm of rain.
Among the 498 cities listed in the United States, Longmont ranks joint 369th of 498 for the warmest October highs and joint 148th of 498 for the driest October (rainfall, lowest first). The mean October high of those 498 cities is 21.4°C; Longmont is 4.6°C cooler than that mean.
From October to November, average highs fall by 7.3°C to 9.4°C, and monthly rainfall falls from 41 mm to 28 mm.
The annual picture
October in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Longmont climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 4.5°C-8.4°C | -8.4°C | 19 | 4.7 | 9.710 h |
| February | 5.9°C-7.6°C | -7.6°C | 20 | 5.3 | 10.611 h |
| March | 11.0°C-3.9°C | -3.9°C | 42 | 7.3 | 11.912 h |
| April | 14.8°C0.4°C | 0.4°C | 67 | 9.5 | 13.213 h |
| May | 19.9°C5.9°C | 5.9°C | 87 | 11.7 | 14.414 h |
| June | 26.0°C11.4°C | 11.4°C | 53 | 8.4 | 15.015 h |
| July | 29.5°C15.0°C | 15.0°C | 42 | 7.3 | 14.715 h |
| August | 28.3°C14.3°C | 14.3°C | 39 | 6.7 | 13.814 h |
| September | 24.2°C9.9°C | 9.9°C | 39 | 5.9 | 12.512 h |
| October, selected | 16.8°C3.2°C | 3.2°C | 41 | 6.5 | 11.211 h |
| November | 9.4°C-3.6°C | -3.6°C | 28 | 5.8 | 10.010 h |
| December | 4.2°C-8.1°C | -8.1°C | 18 | 4.5 | 9.49 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
October in nearby cities
- Boulder in OctoberUnited States · 22 kmHigh 16.5°C · Low 3.1°C · 48 mm rain
- Loveland in OctoberUnited States · 26 kmHigh 16.5°C · Low 2.9°C · 40 mm rain
- Thornton in OctoberUnited States · 35 kmHigh 16.6°C · Low 2.3°C · 40 mm rain
- Westminster (Colorado), United States in OctoberUnited States · 37 kmHigh 16.8°C · Low 2.3°C · 40 mm rain
- Arvada in OctoberUnited States · 41 kmHigh 16.9°C · Low 2.5°C · 40 mm rain
- Greeley in OctoberUnited States · 44 kmHigh 17.9°C · Low 3.9°C · 30 mm rain
- Fort Collins in OctoberUnited States · 47 kmHigh 16.3°C · Low 2.9°C · 40 mm rain
- Denver in OctoberUnited States · 49 kmHigh 17.0°C · Low 2.4°C · 40 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Longmont) is explained once on the Longmont year overview and on the Sources, method and limits page.