Green Bay weather in September
In September, Green Bay sees average daytime highs of 70°F and overnight lows near 52°F, with 2.6 in of rain across 9.1 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 7th-wettest month of the year here.
Highs ease over the month, from about 75°F in the first days to 65°F by the end. The sky is clear or mostly clear about 33% of the time in September, and the air most often feels dry.
Daylight stretches from about 13 h 06 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Green Bay's 2nd-clearest and 9th-windiest month. For the whole year in context, see Green Bay's year-round climate.
- Daytime high
- 70°
- 4th warmest
- Overnight low
- 52°
- 9th coldest
- Rainfall
- 2.6 in
- 9.1 wet days
- Daylight
- 12 h 18 min
- 5:37 AM – 5:56 PM
- Cloud cover
- 56%
- 2nd clearest
- Wind
- 8 mph
- 9th windiest
- Solar energy
- 4.14 kWh/m²
- Travel score
- 6.7
- out of 10
Green Bay is city in and county seat of Brown County, Wisconsin, United States.
- Density
- 727/km²
- people per km²
- Founded
- 1634
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in September
Highs ease over the month, from about 75°F in the first days to 65°F by the end.
A typical September day in Green Bay reaches about 70°F in the afternoon and slips back to 52°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 59°F and 81°F. Set against its neighbours, September runs about 7°F cooler than August and about 14°F warmer than October.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 76 | 75 | 75 | 75 | 74 | 74 | 74 | 73 | 73 | 73 | 72 | 72 | 72 | 71 | 71 | 70 | 70 | 70 | 69 | 69 | 68 | 68 | 67 | 67 | 66 | 66 | 65 | 65 | 65 | 64 |
| Avg low (°F) | 57 | 57 | 56 | 56 | 56 | 56 | 55 | 55 | 55 | 54 | 54 | 53 | 53 | 53 | 52 | 52 | 52 | 51 | 51 | 50 | 50 | 50 | 49 | 49 | 48 | 48 | 47 | 47 | 47 | 46 |
| Avg high (°F) | Avg low (°F) | |
|---|---|---|
| 1 | 76 | 57 |
| 2 | 75 | 57 |
| 3 | 75 | 56 |
| 4 | 75 | 56 |
| 5 | 74 | 56 |
| 6 | 74 | 56 |
| 7 | 74 | 55 |
| 8 | 73 | 55 |
| 9 | 73 | 55 |
| 10 | 73 | 54 |
| 11 | 72 | 54 |
| 12 | 72 | 53 |
| 13 | 72 | 53 |
| 14 | 71 | 53 |
| 15 | 71 | 52 |
| 16 | 70 | 52 |
| 17 | 70 | 52 |
| 18 | 70 | 51 |
| 19 | 69 | 51 |
| 20 | 69 | 50 |
| 21 | 68 | 50 |
| 22 | 68 | 50 |
| 23 | 67 | 49 |
| 24 | 67 | 49 |
| 25 | 66 | 48 |
| 26 | 66 | 48 |
| 27 | 65 | 47 |
| 28 | 65 | 47 |
| 29 | 65 | 47 |
| 30 | 64 | 46 |
How September really feels in Green Bay
Once humidity and wind are folded in, September averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.
September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Green Bay weather by month
How September compares with the rest of the year at a glance. September is the 4th-warmest and 7th-wettest month here — the current month is highlighted below.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 26° / 12° | 1.5 | 7.6 | 6.9 | 9 | 0.0 |
| Feb | 29° / 14° | 1.3 | 6.4 | 5.6 | 10.1 | 0.0 |
| Mar | 40° / 24° | 2.2 | 8.3 | 4.4 | 11.6 | 0.4 |
| Apr | 53° / 35° | 3.1 | 11.4 | 3 | 13.2 | 3.0 |
| May | 66° / 47° | 3.4 | 11.4 | 0.1 | 14.6 | 5.7 |
| Jun | 76° / 57° | 3.6 | 11.2 | 0 | 15.3 | 6.5 |
| Jul | 80° / 62° | 3.5 | 11.3 | 0 | 15 | 6.4 |
| Aug | 78° / 60° | 3.4 | 10.4 | 0 | 13.9 | 6.8 |
| Sep | 70° / 52° | 2.6 | 9.1 | 0 | 12.3 | 6.7 |
| Oct | 57° / 41° | 2.8 | 9.5 | 0.3 | 10.7 | 4.0 |
| Nov | 43° / 29° | 2.1 | 8.2 | 2.4 | 9.4 | 0.7 |
| Dec | 31° / 19° | 1.8 | 7.3 | 5.6 | 8.7 | 0.0 |
Cloud cover in September
The sky is clear or mostly clear about 33% of the time in September.
Beyond those clear spells, partly cloudy skies cover about 18% of September, with mostly cloudy or overcast conditions the remaining 49%. Skies tend to cloud over as the month goes on.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 56 | 56 | 56 | 56 | 56 | 55 | 55 | 54 | 54 | 54 | 53 | 52 | 51 | 50 | 50 | 50 | 50 | 49 | 49 | 49 | 49 | 48 | 47 | 48 | 48 | 48 | 48 | 48 | 48 | 48 |
| Cloudier (%) | 44 | 44 | 44 | 44 | 44 | 45 | 45 | 46 | 46 | 46 | 47 | 48 | 49 | 50 | 50 | 50 | 50 | 51 | 51 | 51 | 51 | 52 | 53 | 52 | 52 | 52 | 52 | 52 | 52 | 52 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 56 | 44 |
| 2 | 56 | 44 |
| 3 | 56 | 44 |
| 4 | 56 | 44 |
| 5 | 56 | 44 |
| 6 | 55 | 45 |
| 7 | 55 | 45 |
| 8 | 54 | 46 |
| 9 | 54 | 46 |
| 10 | 54 | 46 |
| 11 | 53 | 47 |
| 12 | 52 | 48 |
| 13 | 51 | 49 |
| 14 | 50 | 50 |
| 15 | 50 | 50 |
| 16 | 50 | 50 |
| 17 | 50 | 50 |
| 18 | 49 | 51 |
| 19 | 49 | 51 |
| 20 | 49 | 51 |
| 21 | 49 | 51 |
| 22 | 48 | 52 |
| 23 | 47 | 53 |
| 24 | 48 | 52 |
| 25 | 48 | 52 |
| 26 | 48 | 52 |
| 27 | 48 | 52 |
| 28 | 48 | 52 |
| 29 | 48 | 52 |
| 30 | 48 | 52 |
Chance of precipitation in September
Green Bay gets around 2.6 in of rain over 9.1 wet days in September. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 30% and peaks near 32% on the wettest days.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 30 | 30 | 30 | 30 | 29 | 29 | 29 | 29 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 31 | 31 | 31 | 32 | 32 | 32 | 32 | 32 | 32 | 32 |
| Rain chance (%) | |
|---|---|
| 1 | 30 |
| 2 | 30 |
| 3 | 30 |
| 4 | 30 |
| 5 | 29 |
| 6 | 29 |
| 7 | 29 |
| 8 | 29 |
| 9 | 30 |
| 10 | 30 |
| 11 | 30 |
| 12 | 30 |
| 13 | 30 |
| 14 | 30 |
| 15 | 30 |
| 16 | 30 |
| 17 | 30 |
| 18 | 30 |
| 19 | 30 |
| 20 | 30 |
| 21 | 31 |
| 22 | 31 |
| 23 | 31 |
| 24 | 32 |
| 25 | 32 |
| 26 | 32 |
| 27 | 32 |
| 28 | 32 |
| 29 | 32 |
| 30 | 32 |
Humidity in September
Most of September feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, September lands in the dry band about 62% of days. Sticky, muggy-or-worse air turns up on roughly 7% of them.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 39 | 41 | 43 | 44 | 46 | 48 | 49 | 50 | 52 | 53 | 55 | 57 | 58 | 59 | 60 | 62 | 63 | 65 | 66 | 67 | 70 | 71 | 73 | 76 | 77 | 78 | 80 | 81 | 83 | 84 |
| Comfortable (%) | 24 | 23 | 23 | 22 | 22 | 22 | 21 | 21 | 21 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 19 | 19 | 18 | 18 | 17 | 16 | 15 | 14 | 13 | 13 | 12 | 11 | 10 | 9 |
| Humid (%) | 21 | 21 | 20 | 20 | 19 | 19 | 18 | 18 | 17 | 17 | 16 | 15 | 14 | 14 | 13 | 12 | 12 | 11 | 11 | 10 | 9 | 9 | 8 | 7 | 7 | 6 | 6 | 6 | 5 | 5 |
| Muggy (%) | 15 | 14 | 13 | 13 | 12 | 11 | 10 | 10 | 9 | 9 | 8 | 8 | 8 | 7 | 7 | 6 | 6 | 5 | 5 | 5 | 4 | 4 | 4 | 3 | 3 | 3 | 2 | 2 | 2 | 2 |
| Oppressive (%) | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | |
|---|---|---|---|---|---|
| 1 | 39 | 24 | 21 | 15 | 1 |
| 2 | 41 | 23 | 21 | 14 | 1 |
| 3 | 43 | 23 | 20 | 13 | 1 |
| 4 | 44 | 22 | 20 | 13 | 1 |
| 5 | 46 | 22 | 19 | 12 | 1 |
| 6 | 48 | 22 | 19 | 11 | 1 |
| 7 | 49 | 21 | 18 | 10 | 1 |
| 8 | 50 | 21 | 18 | 10 | 1 |
| 9 | 52 | 21 | 17 | 9 | 1 |
| 10 | 53 | 20 | 17 | 9 | 1 |
| 11 | 55 | 20 | 16 | 8 | 1 |
| 12 | 57 | 20 | 15 | 8 | 0 |
| 13 | 58 | 20 | 14 | 8 | 0 |
| 14 | 59 | 20 | 14 | 7 | 0 |
| 15 | 60 | 20 | 13 | 7 | 0 |
| 16 | 62 | 20 | 12 | 6 | 0 |
| 17 | 63 | 19 | 12 | 6 | 0 |
| 18 | 65 | 19 | 11 | 5 | 0 |
| 19 | 66 | 18 | 11 | 5 | 0 |
| 20 | 67 | 18 | 10 | 5 | 0 |
| 21 | 70 | 17 | 9 | 4 | 0 |
| 22 | 71 | 16 | 9 | 4 | 0 |
| 23 | 73 | 15 | 8 | 4 | 0 |
| 24 | 76 | 14 | 7 | 3 | 0 |
| 25 | 77 | 13 | 7 | 3 | 0 |
| 26 | 78 | 13 | 6 | 3 | 0 |
| 27 | 80 | 12 | 6 | 2 | 0 |
| 28 | 81 | 11 | 6 | 2 | 0 |
| 29 | 83 | 10 | 5 | 2 | 0 |
| 30 | 84 | 9 | 5 | 2 | 0 |
Wind in September
Winds average 8 mph in September.
Across September, daily wind ranges from about 7 mph on the calmest days to 9 mph at its breeziest. It stays fairly steady from day to day.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (mph) | 7 | 7 | 7 | 7 | 7 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 9 | 9 | 9 |
| Feels | calm | calm | calm | calm | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze |
| Wind speed (mph) | Feels | |
|---|---|---|
| 1 | 7 | calm |
| 2 | 7 | calm |
| 3 | 7 | calm |
| 4 | 7 | calm |
| 5 | 7 | light breeze |
| 6 | 8 | light breeze |
| 7 | 8 | light breeze |
| 8 | 8 | light breeze |
| 9 | 8 | light breeze |
| 10 | 8 | light breeze |
| 11 | 8 | light breeze |
| 12 | 8 | light breeze |
| 13 | 8 | light breeze |
| 14 | 8 | light breeze |
| 15 | 8 | light breeze |
| 16 | 8 | light breeze |
| 17 | 8 | light breeze |
| 18 | 8 | light breeze |
| 19 | 8 | light breeze |
| 20 | 8 | light breeze |
| 21 | 8 | light breeze |
| 22 | 8 | light breeze |
| 23 | 8 | light breeze |
| 24 | 8 | light breeze |
| 25 | 8 | light breeze |
| 26 | 8 | light breeze |
| 27 | 8 | light breeze |
| 28 | 9 | light breeze |
| 29 | 9 | light breeze |
| 30 | 9 | light breeze |
Sunrise & sunset in September
Daylight runs from about 13 h 06 min at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.
Days shrink by about 90 minutes over September. Sunrise moves from 5:19 AM to 5:54 AM, and sunset from 6:24 PM to 5:28 PM.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 13.1 | 13.0 | 13.0 | 12.9 | 12.9 | 12.8 | 12.8 | 12.7 | 12.7 | 12.6 | 12.6 | 12.5 | 12.5 | 12.4 | 12.4 | 12.3 | 12.3 | 12.2 | 12.1 | 12.1 | 12.0 | 12.0 | 11.9 | 11.9 | 11.8 | 11.8 | 11.7 | 11.7 | 11.6 | 11.6 |
| Sunrise (AM) | 5:19 | 5:20 | 5:22 | 5:23 | 5:24 | 5:25 | 5:26 | 5:28 | 5:29 | 5:30 | 5:31 | 5:32 | 5:34 | 5:35 | 5:36 | 5:37 | 5:38 | 5:40 | 5:41 | 5:42 | 5:43 | 5:45 | 5:46 | 5:47 | 5:48 | 5:49 | 5:51 | 5:52 | 5:53 | 5:54 |
| Sunset (PM) | 6:24 | 6:22 | 6:21 | 6:19 | 6:17 | 6:15 | 6:13 | 6:11 | 6:09 | 6:07 | 6:05 | 6:03 | 6:01 | 5:59 | 5:57 | 5:56 | 5:54 | 5:52 | 5:50 | 5:48 | 5:46 | 5:44 | 5:42 | 5:40 | 5:38 | 5:36 | 5:34 | 5:32 | 5:30 | 5:28 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 13.1 | 5:19 | 6:24 |
| 2 | 13.0 | 5:20 | 6:22 |
| 3 | 13.0 | 5:22 | 6:21 |
| 4 | 12.9 | 5:23 | 6:19 |
| 5 | 12.9 | 5:24 | 6:17 |
| 6 | 12.8 | 5:25 | 6:15 |
| 7 | 12.8 | 5:26 | 6:13 |
| 8 | 12.7 | 5:28 | 6:11 |
| 9 | 12.7 | 5:29 | 6:09 |
| 10 | 12.6 | 5:30 | 6:07 |
| 11 | 12.6 | 5:31 | 6:05 |
| 12 | 12.5 | 5:32 | 6:03 |
| 13 | 12.5 | 5:34 | 6:01 |
| 14 | 12.4 | 5:35 | 5:59 |
| 15 | 12.4 | 5:36 | 5:57 |
| 16 | 12.3 | 5:37 | 5:56 |
| 17 | 12.3 | 5:38 | 5:54 |
| 18 | 12.2 | 5:40 | 5:52 |
| 19 | 12.1 | 5:41 | 5:50 |
| 20 | 12.1 | 5:42 | 5:48 |
| 21 | 12.0 | 5:43 | 5:46 |
| 22 | 12.0 | 5:45 | 5:44 |
| 23 | 11.9 | 5:46 | 5:42 |
| 24 | 11.9 | 5:47 | 5:40 |
| 25 | 11.8 | 5:48 | 5:38 |
| 26 | 11.8 | 5:49 | 5:36 |
| 27 | 11.7 | 5:51 | 5:34 |
| 28 | 11.7 | 5:52 | 5:32 |
| 29 | 11.6 | 5:53 | 5:30 |
| 30 | 11.6 | 5:54 | 5:28 |
Solar energy in September
Average shortwave solar energy reaching the ground each day in September, about 4.14 kWh/m².
For context, solar energy here swings from a low near 1.42 kWh/m² to a high of 6.32 kWh/m² in June across the year — September's 4.14 kWh/m² falls in the middle.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 4.8 | 4.8 | 4.7 | 4.7 | 4.6 | 4.6 | 4.5 | 4.5 | 4.4 | 4.4 | 4.3 | 4.3 | 4.2 | 4.2 | 4.1 | 4.1 | 4.0 | 4.0 | 4.0 | 3.9 | 3.9 | 3.8 | 3.8 | 3.7 | 3.7 | 3.6 | 3.6 | 3.6 | 3.5 | 3.5 |
| Level | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 4.8 | Bright |
| 2 | 4.8 | Bright |
| 3 | 4.7 | Bright |
| 4 | 4.7 | Bright |
| 5 | 4.6 | Bright |
| 6 | 4.6 | Bright |
| 7 | 4.5 | Bright |
| 8 | 4.5 | Bright |
| 9 | 4.4 | Bright |
| 10 | 4.4 | Bright |
| 11 | 4.3 | Bright |
| 12 | 4.3 | Bright |
| 13 | 4.2 | Bright |
| 14 | 4.2 | Bright |
| 15 | 4.1 | Bright |
| 16 | 4.1 | Bright |
| 17 | 4.0 | Bright |
| 18 | 4.0 | Moderate |
| 19 | 4.0 | Moderate |
| 20 | 3.9 | Moderate |
| 21 | 3.9 | Moderate |
| 22 | 3.8 | Moderate |
| 23 | 3.8 | Moderate |
| 24 | 3.7 | Moderate |
| 25 | 3.7 | Moderate |
| 26 | 3.6 | Moderate |
| 27 | 3.6 | Moderate |
| 28 | 3.6 | Moderate |
| 29 | 3.5 | Moderate |
| 30 | 3.5 | Moderate |
Is September a good time to visit Green Bay?
Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
September is a reasonable time to visit Green Bay for sightseeing.
What to pack for Green Bay in September
From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In September, Green Bay sees daytime highs around 70°F and nights near 52°F. Worth packing: rain gear. About 9 days see rain.
Sea temperature near Green Bay in September
The nearest coast averages about 64°F in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 10 mi away) is warmest in August at about 69°F and coldest in March near 34°F.
It's comfortable for a long swim from Aug 9 to Aug 23 — about 0.5 months when the water holds above 68°F.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 37 | 35 | 34 | 37 | 43 | 52 | 65 | 69 | 64 | 55 | 46 | 39 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Cool | Refreshing | Cool | Bracing | Bracing | Bracing |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 37 | Bracing |
| Feb | 35 | Bracing |
| Mar | 34 | Bracing |
| Apr | 37 | Bracing |
| May | 43 | Bracing |
| Jun | 52 | Bracing |
| Jul | 65 | Cool |
| Aug | 69 | Refreshing |
| Sep | 64 | Cool |
| Oct | 55 | Bracing |
| Nov | 46 | Bracing |
| Dec | 39 | Bracing |
UV index in Green Bay in September
Clear-sky midday UV in September peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Green Bay peaks around June 18 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 1 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 1 | 2 | 4 | 5 | 8 | 9 | 8 | 7 | 5 | 3 | 2 | 1 |
| Level | Low | Low | Moderate | High | Very high | Very high | Very high | High | High | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 2 | Low |
| Mar | 4 | Moderate |
| Apr | 5 | High |
| May | 8 | Very high |
| Jun | 9 | Very high |
| Jul | 8 | Very high |
| Aug | 7 | High |
| Sep | 5 | High |
| Oct | 3 | Moderate |
| Nov | 2 | Low |
| Dec | 1 | Low |
Where is Green Bay?
Green Bay sits at 44.5°N, 88.0°W, 591 ft above sea level, in United States. The nearest listed city is Ashwaubenon, 3.7 mi away.
Topography around Green Bay
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Green Bay.
Within 2 miles, the terrain around Green Bay has only modest variations in elevation — a maximum elevation change of 135 ft around an average of 597 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 433 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 728 ft.
The land around Green Bay is covered by artificial surfaces (51%) and trees (30%) within 2 miles, trees (29%) and cropland (21%) within 10 miles, and trees (30%), cropland (30%) and water (28%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Green Bay (44.5192°, -88.0198°, elevation 591 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).