Arvada, CO weather in September
Expect mild weather with some rain in Arvada in September, with highs near 79°F and lows near 45°F. Rain or snow falls on about 7 days. Snowfall averages about 1.0 in. Good for outdoor plans.
- Normal high
- 79°F
- Normal low
- 45°F
- Wet days
- 7
- 1.3 in total
- Snowfall
- 1.0 in
- normal snowfall
How September changes from start to finish
| September 1 | September 30 | |
|---|---|---|
| Normal high | 84°F | 73°F |
| Normal low | 51°F | 39°F |
| Chance of a wet day | 24% | 21% |
| Sunrise / sunset | 6:28 am / 7:32 pm | 6:55 am / 6:44 pm |
| Daylight | 13.1 h | 11.8 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 September day
- 6 am52°Fdew point 40°F
- 9 am65°Fdew point 40°F
- Noon74°Fdew point 36°F
- 3 pm76°Fdew point 35°F
- 6 pm68°Fdew point 39°F
- 9 pm60°Fdew point 41°F
NOAA hourly normals (local standard time) from Aurora Buckley Fld ANGB (19 mi away); average wind 8 mph; clear or few clouds in 46% of daytime hours, mostly cloudy or overcast in 35%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F11 of 30
- Hot dayshigh 90°F or more3 of 30
- Muggy daysdaily mean dew point 65°F or more0 of 30
- Wet daysat least 0.01 in of rain or melted snow7 of 30
- Notable rainat least 0.10 in4 of 30
- Freezing nightslow 32°F or below1 of 30
- Snow on the groundsnow depth 1 in or more0 of 30
Average days per September, counted from daily records for each year 1991-2020.
Rain and snow in September
Normal precipitation is 1.3 in; a dry September brings about 0.6 in and a wet one about 1.8 in (25th and 75th percentiles). About 1 day brings half an inch or more. Normal snowfall is 1.0 in.
How September varies from year to year
- Warmest September, 1991-20202015: average high 84°F
- Coolest September2006: average high 73°F
- Wettest September2013: 7.7 in
- Driest September1992: no measurable precipitation
- Highest reading98°F (September 6, 2020)
- Lowest reading24°F (September 29, 1999)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
September compared with August and October
| August | September | October | |
|---|---|---|---|
| Normal high | 86°F | 79°F | 66°F |
| Normal low | 55°F | 45°F | 34°F |
| Wet days | 8 | 7 | 6 |
| Comfortable days | 5 | 11 | 14 |
| Daylight | 13.7 h | 12.4 h | 11.1 h |
Highs change by -7°F from August and -13°F into October.
Nearby alternatives in September
- Cooler: Estes Park, CO46 mi · high 70°F · 9 wet days
How Arvada ranks in September
- Normal high210th warmest of 378 cities; 5th of 17 in Colorado
- Wet days144th driest of 378
- Comfortable days148th most of 342
What to pack for Arvada in September
- Layers – afternoons near 79°F but nights near 45°F
Heating and cooling
September has 135 heating degree days and 48 cooling degree days (base 65°F), 3% of the year's total heating and cooling demand.
Questions
How hot is Arvada in September?
The normal high is 79°F and the normal low is 45°F. From 1991 to 2020 the hottest September reading was 98°F (most recently on September 6, 2020).
Does it rain a lot in Arvada in September?
About 7 days in September have at least 0.01 in of precipitation, and the normal total is 1.3 in. The wettest September in 1991-2020 was in 2013 (7.7 in); the driest was in 1992, with no measurable precipitation.
Does it snow in Arvada in September?
Yes. Normal snowfall in September is 1.0 in.
Is September a good time to visit Arvada?
September ranks 5th of 12 months on our comfort score for Arvada (62 out of 100). It has about 11 comfortable days and about 3 days at 90°F or hotter. The best month is May.
Where the numbers come from
- Temperature, rain, snowfall, snow depth and frost dates: Wheat Ridge 2 (USC00058995), 2.5 mi SW of the city center, 5,398 ft . NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour and cloud cover: Aurora Buckley Fld ANGB (USW00023036), 19 mi ESE of the city center, 5,663 ft (314 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Buckley Air Force Base (724695-23036), 19 mi ESE of the city center, 5,663 ft (314 ft higher than the city). Hourly observations, 1991-2020.