As of 05:15 MDT

Longmont, CO weather in September

69°

Longmont, Sunday, 9 August, 05:15

Partly cloudy. Feels like 67°. High 97°, low 69°.

Pressure29.88 inHg

Wind2 mph SW

Humidity38%

Visibility6.2 mi

Dew point41°

See detailed hourly forecast

In September, Longmont, CO averages a high of 75.2° and a low of 49.4°. About 1.6 inches of precipitation fall over the month (6 wet days). The record high is 98.6° (2020) and the record low 13.8° (1995). Normals are computed over the last 60 years.

Day	High	Low	Chance of precip.	Record high	Record low
1	81°	54.3°	20%	94.5° (2019)	43.7° (1965)
2	80.6°	54.3°	18%	97.5° (2019)	41.5° (1974)
3	81°	54°	13%	93° (2017)	37.9° (1961)
4	80.6°	53.8°	17%	93° (1960)	41.7° (1961)
5	80.8°	54°	18%	97.3° (2020)	43.5° (1962)
6	80.2°	54°	13%	98.6° (2020)	43.7° (1968)
7	79.2°	53.8°	18%	94.3° (2020)	44.8° (1986)
8	78.6°	51.8°	20%	97.5° (2022)	32.2° (2020)
9	77.4°	51.6°	18%	92.7° (2021)	31.1° (2020)
10	77.4°	51.8°	30%	94.3° (2021)	26.6° (2020)
11	75.9°	51.8°	32%	93.4° (2021)	36.9° (2020)
12	74.5°	50.5°	28%	90.9° (2018)	34.5° (2014)
13	74.3°	49.3°	33%	91.6° (2018)	34.3° (1993)
14	74.1°	49.3°	27%	89.6° (2018)	33.1° (1993)
15	74.3°	49.1°	27%	90.3° (2018)	37° (1993)
16	74.8°	48.9°	20%	90.9° (2018)	32° (1965)
17	74.7°	48.6°	18%	90.7° (2000)	28.8° (1965)
18	74.3°	48°	18%	87.8° (2018)	28.8° (1971)
19	74.1°	48.4°	20%	88.5° (2022)	19.9° (1971)
20	72.9°	47.5°	20%	88.7° (2022)	27.9° (1971)
21	70.9°	46.8°	25%	84.6° (2005)	28.2° (1965)
22	69.8°	45.3°	27%	85.5° (2007)	13.8° (1995)
23	71.2°	45.9°	20%	86.2° (2018)	24.4° (1971)
24	71.6°	45.9°	23%	88.2° (2020)	28.4° (1965)
25	71.6°	45.1°	20%	86.5° (2020)	21.9° (2000)
26	73.6°	45.3°	18%	89.1° (2024)	25.2° (1970)
27	72.1°	45.5°	18%	86.7° (2015)	25.2° (1996)
28	70.9°	45.1°	20%	86.9° (2010)	27.9° (1985)
29	72.1°	45.3°	17%	87.1° (2019)	19.6° (1999)
30	70.9°	45.7°	13%	84.6° (1980)	15.6° (1985)