Lewiston, ME weather in September
Lewiston is mild in September, with some rain: highs average 70°F and nights drop to about 47°F. There are about 10 days with rain. A great month for outdoor plans.
- Normal high
- 70°F
- Normal low
- 47°F
- Wet days
- 10
- 4.2 in total
- Muggy days
- 1
- dew point 65°F+
How September changes from start to finish
| September 1 | September 30 | |
|---|---|---|
| Normal high | 75°F | 65°F |
| Normal low | 51°F | 41°F |
| Chance of a wet day | 32% | 35% |
| Sunrise / sunset | 6:04 am / 7:17 pm | 6:37 am / 6:24 pm |
| Daylight | 13.2 h | 11.8 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Eastern Time).
A typical September day
- 6 am54°Fdew point 51°F
- 9 am61°Fdew point 52°F
- Noon67°Fdew point 51°F
- 3 pm69°Fdew point 51°F
- 6 pm63°Fdew point 52°F
- 9 pm58°Fdew point 52°F
NOAA hourly normals (local standard time) from Augusta State Airport (26 mi away); average wind 7 mph.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F17 of 30
- Hot dayshigh 90°F or more0 of 30
- Muggy daysdaily mean dew point 65°F or more1 of 30
- Wet daysat least 0.01 in of rain or melted snow10 of 30
- Notable rainat least 0.10 in6 of 30
- Freezing nightslow 32°F or below1 of 30
- Snow on the groundsnow depth 1 in or more0 of 30
Average days per September, counted from daily records for each year 1991-2020.
Rain in September
Normal precipitation is 4.2 in; a dry September brings about 2.4 in and a wet one about 5.0 in (25th and 75th percentiles). About 3 days bring half an inch or more, and about 1 an inch or more.
How September varies from year to year
- Warmest September, 1991-20202015: average high 78°F
- Coolest September2008: average high 67°F
- Wettest September2008: 11.1 in
- Driest September2020: 0.8 in
- Highest reading97°F (September 4, 1999)
- Lowest reading27°F (September 30, 2000)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
September compared with August and October
| August | September | October | |
|---|---|---|---|
| Normal high | 78°F | 70°F | 58°F |
| Normal low | 54°F | 47°F | 36°F |
| Wet days | 11 | 10 | 12 |
| Comfortable days | 12 | 17 | 7 |
| Daylight | 14.0 h | 12.5 h | 11.0 h |
Highs change by -8°F from August and -12°F into October.
Nearby alternatives in September
- Warmer: Lowell, MA115 mi · high 76°F · 9 wet days
How Lewiston ranks in September
- Normal high344th warmest of 378 cities; 4th of 5 in Maine
- Wet days294th driest of 378
- Comfortable days37th most of 342
What to pack for Lewiston in September
- A rain jacket or umbrella – rain on about 10 days
Heating and cooling
September has 218 heating degree days and 22 cooling degree days (base 65°F), 3% of the year's total heating and cooling demand.
Questions
How hot is Lewiston in September?
The normal high is 70°F and the normal low is 47°F. From 1991 to 2020 the hottest September reading was 97°F (September 4, 1999).
Does it rain a lot in Lewiston in September?
About 10 days in September have at least 0.01 in of precipitation, and the normal total is 4.2 in. The wettest September in 1991-2020 was in 2008 (11.1 in); the driest was in 2020 (0.8 in).
Is September a good time to visit Lewiston?
September ranks 3rd of 12 months on our comfort score for Lewiston (71 out of 100). It has about 17 comfortable days. The best months are May, June and September.
Where the numbers come from
- Temperature, rain, snowfall and snow depth: Durham (USC00172048), 9.1 mi SE of the city center, 140 ft (78 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Frost dates: Lewiston (USC00174566), 0.1 mi WSW of the city center, 180 ft . NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour: Augusta State Airport (USW00014605), 26 mi NE of the city center, 350 ft (132 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Augusta State Airport (726185-14605), 26 mi NE of the city center, 349 ft (131 ft higher than the city). Hourly observations, 1991-2020.
- Not available for this location: cloud cover (no station close enough or similar enough in elevation).