Climate averages 1991–2020
Lowell weather
in September.
A warm, moderately wet month: the 4th warmest and the joint 5th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a warm month in Lowell: daytime highs average 22.6°C and nights cool to about 13.8°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 84 mm of rain on roughly 8 days, which makes September a moderately wet month (the joint 5th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 32 min on an average September day.
The nearest other city in this atlas is Lawrence (Massachusetts), United States (15 km away). In September its highs average 22.7°C, about as warm as Lowell, with 84 mm of rain.
Among the 498 cities listed in the United States, Lowell ranks joint 424th of 498 for the warmest September highs and joint 300th of 498 for the driest September (rainfall, lowest first). The mean September high of those 498 cities is 26.9°C; Lowell is 4.3°C cooler than that mean.
From September to October, average highs fall by 6.7°C to 15.9°C, and monthly rainfall rises from 84 mm to 96 mm.
The annual picture
September in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Lowell climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 1.1°C-7.5°C | -7.5°C | 80 | 9.6 | 9.49 h |
| February | 2.7°C-6.6°C | -6.6°C | 76 | 8.8 | 10.511 h |
| March | 6.8°C-2.6°C | -2.6°C | 104 | 10.9 | 11.912 h |
| April | 13.5°C3.4°C | 3.4°C | 95 | 10.5 | 13.413 h |
| May | 19.2°C9.3°C | 9.3°C | 78 | 10.4 | 14.615 h |
| June | 24.5°C14.8°C | 14.8°C | 87 | 10.6 | 15.315 h |
| July | 27.8°C18.2°C | 18.2°C | 82 | 9.7 | 15.015 h |
| August | 26.9°C17.6°C | 17.6°C | 84 | 9.3 | 13.914 h |
| September, selected | 22.6°C13.8°C | 13.8°C | 84 | 8.2 | 12.513 h |
| October | 15.9°C7.7°C | 7.7°C | 96 | 9.5 | 11.111 h |
| November | 9.6°C2.0°C | 2.0°C | 86 | 9.3 | 9.810 h |
| December | 4.0°C-3.4°C | -3.4°C | 104 | 10.3 | 9.19 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Lawrence (Massachusetts), United States in SeptemberUnited States · 15 kmHigh 22.7°C · Low 14.0°C · 84 mm rain
- Nashua in SeptemberUnited States · 19 kmHigh 22.5°C · Low 13.4°C · 86 mm rain
- Newton in SeptemberUnited States · 34 kmHigh 22.6°C · Low 14.4°C · 85 mm rain
- Lynn in SeptemberUnited States · 35 kmHigh 21.0°C · Low 14.8°C · 87 mm rain
- Boston in SeptemberUnited States · 37 kmHigh 22.4°C · Low 14.1°C · 88 mm rain
- Manchester, United States in SeptemberUnited States · 42 kmHigh 22.3°C · Low 13.0°C · 87 mm rain
- Dorchester in SeptemberUnited States · 42 kmHigh 22.2°C · Low 14.4°C · 88 mm rain
- Quincy in SeptemberUnited States · 50 kmHigh 21.9°C · Low 14.8°C · 88 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Lowell) is explained once on the Lowell year overview and on the Sources, method and limits page.
Lawrence (Massachusetts), United States lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.