Duluth, MN weather in September
In September, Duluth sees highs around 67°F and lows around 50°F: mild, with some rain. Rain falls on about 10 days. Good for outdoor plans.
- Normal high
- 67°F
- Normal low
- 50°F
- Wet days
- 10
- 3.4 in total
- Muggy days
- 0
- dew point 65°F+
How September changes from start to finish
| September 1 | September 30 | |
|---|---|---|
| Normal high | 72°F | 61°F |
| Normal low | 55°F | 45°F |
| Chance of a wet day | 33% | 32% |
| Sunrise / sunset | 6:28 am / 7:48 pm | 7:05 am / 6:50 pm |
| Daylight | 13.3 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 (Central Time).
A typical September day
- 6 am50°Fdew point 47°F
- 9 am57°Fdew point 49°F
- Noon63°Fdew point 49°F
- 3 pm64°Fdew point 48°F
- 6 pm59°Fdew point 49°F
- 9 pm54°Fdew point 48°F
NOAA hourly normals (local standard time) from Duluth (6 mi away); average wind 9 mph; clear or few clouds in 45% of daytime hours, mostly cloudy or overcast in 39%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F13 of 30
- Beach dayshigh 80-95°F, under 0.05 in of rain, afternoon wind under 15 mph2 of 30
- Hot dayshigh 90°F or more0 of 30
- Muggy daysdaily mean dew point 65°F or more0 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 3.4 in; a dry September brings about 2.0 in and a wet one about 4.3 in (25th and 75th percentiles). About 2 days bring half an inch or more, and about 1 an inch or more.
How September varies from year to year
- Warmest September, 1991-20201998: average high 72°F
- Coolest September1993: average high 60°F
- Wettest September1991: 8.5 in
- Driest September2020: 0.3 in
- Highest reading91°F (September 7, 2002)
- Lowest reading29°F (September 24, 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 | 75°F | 67°F | 53°F |
| Normal low | 58°F | 50°F | 39°F |
| Wet days | 10 | 10 | 10 |
| Comfortable days | 16 | 13 | 4 |
| Daylight | 14.2 h | 12.6 h | 10.9 h |
Highs change by -8°F from August and -14°F into October.
Nearby alternatives in September
- Warmer: Minneapolis, MN136 mi · high 73°F · 9 wet days
How Duluth ranks in September
- Normal high367th warmest of 378 cities; 3rd of 3 in Minnesota
- Wet days307th driest of 378
- Comfortable days122nd most of 342
What to pack for Duluth in September
- A rain jacket or umbrella – rain on about 10 days
Heating and cooling
September has 221 heating degree days and 21 cooling degree days (base 65°F), 3% of the year's total heating and cooling demand.
Questions
How cold is Duluth in September?
The normal high is 67°F and the normal low is 50°F. From 1991 to 2020 the coldest September reading was 29°F (September 24, 2000).
Does it rain a lot in Duluth in September?
About 10 days in September have at least 0.01 in of precipitation, and the normal total is 3.4 in. The wettest September in 1991-2020 was in 1991 (8.5 in); the driest was in 2020 (0.3 in).
Is September a good time to visit Duluth?
September ranks 4th of 12 months on our comfort score for Duluth (66 out of 100). It has about 13 comfortable days. The best month is August.
Where the numbers come from
- Temperature, rain, snowfall, snow depth and frost dates: Superior (USC00478349), 4.2 mi SSE of the city center, 607 ft (93 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour and cloud cover: Duluth (USW00014913), 6.1 mi NW of the city center, 1,428 ft (728 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Duluth International Airport (727450-14913), 5.7 mi NW of the city center, 1,422 ft (722 ft higher than the city). Hourly observations, 1991-2020.