As of 18:18 MDT

Boulder, CO weather in September

91°

Boulder, Saturday, 8 August, 18:18

Overcast. Feels like 87°. High 96°, low 66°.

Pressure29.71 inHg

Wind2 mph SE

Humidity20%

Visibility6.2 mi

Dew point43°

See detailed hourly forecast

In September, Boulder, CO averages a high of 74.5° and a low of 48.5°. About 2.1 inches of precipitation fall over the month (10 wet days). The record high is 95° (2020) and the record low 9° (1995). Normals are computed over the last 60 years.

Day	High	Low	Chance of precip.	Record high	Record low
1	80.1°	53.6°	37%	94.3° (2019)	42.3° (1965)
2	79.7°	53.4°	38%	94.8° (2019)	41° (1974)
3	80.2°	53.1°	30%	92.5° (2017)	36.5° (1961)
4	79.7°	52.9°	33%	91.8° (1960)	41.2° (1961)
5	80.1°	53.1°	25%	94.3° (2020)	43.5° (1962)
6	79.3°	52.9°	40%	95° (2020)	42.6° (1968)
7	78.3°	52.7°	33%	93° (2022)	43.3° (2010)
8	77.7°	51.1°	38%	94.3° (2022)	30.6° (2020)
9	76.6°	51.1°	40%	90° (2021)	29.8° (2020)
10	76.5°	50.9°	50%	92.3° (2021)	27.3° (2020)
11	75°	50.9°	47%	91.4° (2021)	32° (2020)
12	73.6°	49.8°	47%	89.2° (2018)	33.4° (2014)
13	73.4°	48.7°	50%	90° (1990)	33.3° (1993)
14	73.4°	48.6°	47%	88.9° (2018)	28.6° (1993)
15	73.8°	48.7°	32%	89.1° (2018)	35.4° (1993)
16	74.3°	48.4°	28%	89.6° (2000)	31.6° (1965)
17	73.9°	47.8°	27%	89.8° (2000)	27.5° (1965)
18	73.8°	47.1°	30%	86° (2021)	28.4° (1971)
19	73.8°	47.7°	28%	87.4° (2010)	17.6° (1971)
20	72.1°	46.9°	33%	87.4° (2010)	25° (1971)
21	70.2°	46.2°	42%	84.4° (2015)	23° (1965)
22	69.1°	44.2°	37%	85.3° (2007)	9° (1995)
23	70.9°	45.1°	28%	83.8° (2018)	18.7° (1971)
24	70.7°	45.1°	30%	85.3° (2020)	24.4° (1971)
25	71.1°	44.1°	27%	84.9° (2020)	18.1° (2000)
26	72.7°	44.2°	25%	88° (2024)	16.5° (1970)
27	71.8°	44.6°	25%	86° (2015)	20.5° (1996)
28	70.2°	44.1°	23%	86.7° (2010)	27.7° (1985)
29	71.6°	44.6°	20%	86° (2018)	12.4° (1999)
30	70.2°	44.6°	20%	84.7° (1980)	11.8° (1985)