Longmont in September
8.3out of 10
Yes, a good time to go
Warm and comfortable: highs around 26°C. Some rain: about 6 rainy days.
26°CAvg high
10°CAvg low
6Rainy days (39 mm)
12:15 hDaylight
06:47Sunrise · 19:02 Sunset
Why this score
- Warm and comfortable: highs around 26°C
- Some rain: about 6 rainy days
What to wear and pack
- T-shirts and light layers
- A light jacket for cooler evenings
How reliable is the forecast?
Rainfall in September is fairly consistent from year to year (3.0 days). Averages cover 30 years (1991–2020). Individual days can differ a lot.
Year at a glance
Weather by month
| Month | Avg high | Avg low | Rainfall | Rainy days | Humidity | Sunshine | Score |
|---|---|---|---|---|---|---|---|
| January | 6°C | -7°C | 19 mm | 5 | – | – | 5.3 |
| February | 8°C | -6°C | 20 mm | 5 | – | – | 5.6 |
| March | 14°C | -2°C | 42 mm | 7 | – | – | 6.4 |
| April | 17°C | 2°C | 67 mm | 9 | – | – | 7.0 |
| May | 22°C | 7°C | 87 mm | 12 | – | – | 7.4 |
| June | 28°C | 12°C | 53 mm | 9 | – | – | 7.9 |
| July | 31°C | 15°C | 42 mm | 8 | – | – | 7.6 |
| August | 30°C | 14°C | 39 mm | 7 | – | – | 8.0 |
| September | 26°C | 10°C | 39 mm | 6 | – | – | 8.3 |
| October | 19°C | 3°C | 41 mm | 7 | – | – | 7.7 |
| November | 11°C | -3°C | 28 mm | 6 | – | – | 6.2 |
| December | 6°C | -7°C | 18 mm | 4 | – | – | 5.3 |
Frequently asked questions
How hot is Longmont in September?
Daytime highs average 26°C and nights about 10°C.
When is the best time to visit Longmont?
The best months are September, August, June.