ClimateAverages

Longmont Weather in September

JanFebMarAprMayJunJulAugSepOctNovDec
September daytime high
25.6°C
September overnight low
7.6°C
September average
16.6°C

In September, Longmont typically sees daytime highs of 25.6°C and overnight lows around 7.6°C. Compared to the annual average high of 18.2°C, September runs +7.4°C.

vs. annual avg high
+7.4°C
Rank among 12 months
#4 warmest
Hottest year overall
1933

Where September ranks in Longmont

JanFebMarAprMayJunJulAugSep26°OctNovDec

FAQ

What is the average temperature in Longmont in September?

September in Longmont averages a daytime high of 25.6°C and an overnight low of 7.6°C.

Is September warm or cold in Longmont?

September runs +7.4°C compared to Longmont's annual average high of 18.2°C, ranking #4 of 12 months by warmth.

What should I pack for Longmont in September?

Plan for daytime highs near 25.6°C and cooler evenings around 7.6°C.

Other months for Longmont

JanuaryFebruaryMarchAprilMayJuneJulyAugustOctoberNovemberDecember

September in nearby cities

DenverColorado SpringsAuroraFort CollinsLakewoodThorntonArvadaWestminsterCentennialPuebloBoulderGreeley