Boulder, CO weather in October
October in Boulder: mild, with some rain and some snow. Highs 66°F, lows 37°F, rain or snow on about 7 days and about 7.0 in of snow. A good month for most outdoor plans.
- Normal high
- 66°F
- Normal low
- 37°F
- Wet days
- 7
- 1.6 in total
- Snowfall
- 7.0 in
- snow on the ground 2 days
How October changes from start to finish
| October 1 | October 31 | |
|---|---|---|
| Normal high | 72°F | 60°F |
| Normal low | 42°F | 33°F |
| Chance of a wet day | 23% | 22% |
| Sunrise / sunset | 6:57 am / 6:44 pm | 7:29 am / 6:00 pm |
| Daylight | 11.8 h | 10.5 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Mountain Time).
A typical October day
- 6 am42°Fdew point 28°F
- 9 am52°Fdew point 30°F
- Noon61°Fdew point 28°F
- 3 pm63°Fdew point 27°F
- 6 pm53°Fdew point 29°F
- 9 pm47°Fdew point 29°F
NOAA hourly normals (local standard time) from Denver Intl Airport (35 mi away); average wind 10 mph; clear or few clouds in 46% of daytime hours, mostly cloudy or overcast in 38%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F16 of 31
- Hot dayshigh 90°F or more0 of 31
- Muggy daysdaily mean dew point 65°F or more0 of 31
- Wet daysat least 0.01 in of rain or melted snow7 of 31
- Notable rainat least 0.10 in4 of 31
- Freezing nightslow 32°F or below8 of 31
- Snow on the groundsnow depth 1 in or more2 of 31
Average days per October, counted from daily records for each year 1991-2020.
Rain and snow in October
Normal precipitation is 1.6 in; a dry October brings about 0.9 in and a wet one about 2.4 in (25th and 75th percentiles). About 1 day brings half an inch or more. Normal snowfall is 7.0 in, with about 1 day of an inch or more.
How October varies from year to year
- Warmest October, 1991-20202016: average high 75°F
- Coolest October2009: average high 57°F
- Wettest October2006: 3.7 in
- Driest October1996: 0.3 in
- Highest reading89°F (October 2, 2005)
- Lowest reading3°F (October 31, 2019)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
October compared with September and November
| September | October | November | |
|---|---|---|---|
| Normal high | 79°F | 66°F | 55°F |
| Normal low | 48°F | 37°F | 28°F |
| Wet days | 8 | 7 | 6 |
| Comfortable days | 13 | 16 | 8 |
| Daylight | 12.4 h | 11.1 h | 10.0 h |
Highs change by -13°F from September and -11°F into November.
Nearby alternatives in October
- Warmer: Moab, UT250 mi · high 74°F · 5 wet days
- Cooler: Estes Park, CO28 mi · high 57°F · 7 wet days
How Boulder ranks in October
- Normal high235th warmest of 378 cities; 6th of 17 in Colorado
- Wet days148th driest of 378
- Comfortable days56th most of 340
What to pack for Boulder in October
- A warm jacket – lows near 37°F, highs near 66°F
- Layers – afternoons near 66°F but nights near 37°F
- Waterproof boots – about 7.0 in of snow in a typical year
Frost in October
The first fall frost typically comes around Oct 5; in 1 year in 10 it comes before Sep 21. All frost dates for Boulder.
Heating and cooling
October has 421 heating degree days and 5 cooling degree days (base 65°F), 7% of the year's total heating and cooling demand.
Questions
How cold is Boulder in October?
The normal high is 66°F and the normal low is 37°F. From 1991 to 2020 the coldest October reading was 3°F (most recently on October 31, 2019).
Does it rain a lot in Boulder in October?
About 7 days in October have at least 0.01 in of precipitation, and the normal total is 1.6 in. The wettest October in 1991-2020 was in 2006 (3.7 in); the driest was in 1996 (0.3 in).
Does it snow in Boulder in October?
Yes. Normal snowfall in October is 7.0 in, and snow covers the ground on about 2 days.
Is October a good time to visit Boulder?
October ranks 5th of 12 months on our comfort score for Boulder (66 out of 100). It has about 16 comfortable days. The best month is May.
Where the numbers come from
- Temperature, rain, snowfall, snow depth and frost dates: Boulder (USC00050848), 1.6 mi S of the city center, 5,484 ft (165 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour: Denver Intl Airport (USW00003017), 35 mi ESE of the city center, 5,414 ft (95 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Cloud cover: Aurora Buckley Fld ANGB (USW00023036), 35 mi SE of the city center, 5,663 ft (344 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Denver International Airport (725650-03017), 35 mi ESE of the city center, 5,404 ft (85 ft higher than the city). Hourly observations, 1991-2020.