Gresham, United States — Weather in September 2026

Monthly climate averages for Gresham, United States. Based on 10-year ERA5 reanalysis data.

Csa Hot-Summer Mediterranean
8.3 /10
Excellent

September is an excellent month in Gresham

Climate Overview

Gresham, United States in September has warm conditions, with highs averaging 24.5°C (76°F). Temperatures drop noticeably between day and night.

This month falls at the beginning of Autumn.

Daily highs in September gradually drop from around 29°C (83°F) at the start to 22°C (72°F) by month's end.

Rainfall is heaviest during the last third of the month, while the first third tends to be drier.

Expect around 11.2h of sunshine at the start of September, decreasing to 8.8h by the end.

The warmest days tend to fall around the 4th, averaging 28.9°C (84°F).

Compared to August, this month is about 5°C cooler with 6 more rainy days. Temperatures begin dropping heading into October.

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Monthly September Averages

Temperature
25°C / 12°C
Feels Like
24°C / 12°C
Rain
8 days · 58 mm
Sunshine
9.9h / day
Humidity
68% — Humid
Wind
11 km/h
Wind Direction
WNW (289°)
Gusts
30 km/h
Daylight
12.5 h
Cloud Cover
49%
Clear Sky Days
7.7
UV Index
5 — Moderate
Dew Point
12°C — Comfortable
Moon Phase
Waxing Crescent · 11%

Climate Charts

Daily averages based on historical data (2016–2025)

Daily Temperature

36°C 31°C 26°C 21°C 16°C 11°C 6°C 151015202530
HighLow

Daily Precipitation

0 mm 2 mm 4 mm 6 mm 8 mm 151015202530
Rainfall

Daily Sunshine

0h 3h 6h 9h 12h 151015202530
Sunshine

Daily Wind Speed

0 4 8 12 16 20 151015202530
Wind Speed
Sun Position
Sunrise 06:50
Daylight 12.6h
Sunset 19:23

What to Expect

Daytime temperatures around 25°C (76°F) are ideal for full-day outdoor exploration.

Rain usually comes in shorter passing showers rather than all-day rain.

3 of the last 5 yearly records were warmer than this month's long-run average.

Compare Months

January
Wet
Temp
8°C / 2°C
Feels Like
5°C / -2°C
Rain
19days (224 mm) Wet
Sun
4.4h Fair
Humidity
86% Very Muggy
UV
1.6 Low
Snow Days
5days
View Details
February
Wet
Temp
8°C / 1°C
Feels Like
6°C / -2°C
Rain
18days (193 mm) Wet
Sun
5.5h Fair
Humidity
85% Humid
UV
2.3 Moderate
Snow Days
8days
View Details
March
Wet
Temp
12°C / 3°C
Feels Like
9°C / -1°C
Rain
20days (174 mm) Wet
Sun
7.4h Good
Humidity
83% Humid
UV
3.7 Moderate
Snow Days
5days
View Details
April
Fair
Temp
16°C / 5°C
Feels Like
14°C / 2°C
Rain
16days (138 mm) Wet
Sun
9.1h Good
Humidity
77% Humid
UV
5.4 High
Snow Days
2days
View Details
May
Good
Temp
20°C / 9°C
Feels Like
19°C / 7°C
Rain
11days (75 mm) Wet
Sun
10.8h Excellent
Humidity
73% Muggy
UV
6.1 High
View Details
June best
Excellent
Temp
24°C / 12°C
Feels Like
23°C / 11°C
Rain
9days (61 mm) Wet
Sun
12.1h Excellent
Humidity
69% Muggy
UV
6.7 High
View Details
July best
Excellent
Temp
28°C / 14°C
Feels Like
28°C / 14°C
Rain
2days (6 mm) Excellent
Sun
13.2h Excellent
Humidity
60% Moderate
UV
7.3 Very High
View Details
August best
Excellent
Temp
29°C / 15°C
Feels Like
29°C / 15°C
Rain
2days (11 mm) Excellent
Sun
11.9h Excellent
Humidity
59% Moderate
UV
6.4 High
View Details
September best
Excellent
Temp
25°C / 12°C
Feels Like
24°C / 12°C
Rain
8days (58 mm) Wet
Sun
9.9h Good
Humidity
68% Muggy
UV
5 Moderate
View Details
October
Good
Temp
17°C / 8°C
Feels Like
16°C / 6°C
Rain
14days (163 mm) Wet
Sun
7.2h Good
Humidity
79% Humid
UV
3.2 Moderate
View Details
November
Wet
Temp
11°C / 5°C
Feels Like
9°C / 2°C
Rain
18days (218 mm) Wet
Sun
5.2h Fair
Humidity
86% Very Muggy
UV
1.9 Low
Snow Days
1days
View Details
December
Wet
Temp
8°C / 2°C
Feels Like
5°C / -1°C
Rain
20days (258 mm) Wet
Sun
4h Fair
Humidity
88% Very Muggy
UV
1.2 Low
Snow Days
5days
View Details
Month Temp Feels Like Rain Sun Humidity UV Status
January 8°C / 2°C 5°C / -2°C 19days (224 mm) Wet 4.4h Fair 86% Very Muggy 1.6 Low Wet View Details
February 8°C / 1°C 6°C / -2°C 18days (193 mm) Wet 5.5h Fair 85% Humid 2.3 Moderate Wet View Details
March 12°C / 3°C 9°C / -1°C 20days (174 mm) Wet 7.4h Good 83% Humid 3.7 Moderate Wet View Details
April 16°C / 5°C 14°C / 2°C 16days (138 mm) Wet 9.1h Good 77% Humid 5.4 High Fair View Details
May 20°C / 9°C 19°C / 7°C 11days (75 mm) Wet 10.8h Excellent 73% Muggy 6.1 High Good View Details
June best 24°C / 12°C 23°C / 11°C 9days (61 mm) Wet 12.1h Excellent 69% Muggy 6.7 High Excellent View Details
July best 28°C / 14°C 28°C / 14°C 2days (6 mm) Excellent 13.2h Excellent 60% Moderate 7.3 Very High Excellent View Details
August best 29°C / 15°C 29°C / 15°C 2days (11 mm) Excellent 11.9h Excellent 59% Moderate 6.4 High Excellent View Details
September best 25°C / 12°C 24°C / 12°C 8days (58 mm) Wet 9.9h Good 68% Muggy 5 Moderate Excellent View Details
October 17°C / 8°C 16°C / 6°C 14days (163 mm) Wet 7.2h Good 79% Humid 3.2 Moderate Good View Details
November 11°C / 5°C 9°C / 2°C 18days (218 mm) Wet 5.2h Fair 86% Very Muggy 1.9 Low Wet View Details
December 8°C / 2°C 5°C / -1°C 20days (258 mm) Wet 4h Fair 88% Very Muggy 1.2 Low Wet View Details

What to Wear

Summer clothing like shorts, t-shirts, and sundresses will be comfortable. Bring a light cardigan for air-conditioned spaces.

Temperatures drop significantly at night, so pack layers you can add or remove throughout the day.

A waterproof jacket or compact umbrella is recommended for occasional showers.

Packing List

UmbrellaBreathable clothingSunscreen (SPF 30+)Sun hatSunglassesComfortable walking shoes

Frequently Asked Questions

September is typically excellent for visiting Gresham, with average highs of 25°C (76°F) and around 8 rainy days. Gresham, United States in September has warm conditions, with highs averaging 24.5°C (76°F). Temperatures drop noticeabl
Gresham typically sees around 8 rainy days in September with 58 mm (2.3 in) of total rainfall. An umbrella should suffice.
Nights in Gresham during September are cool at around 12°C (54°F). Bring a jacket or sweater for evenings.
With highs of 25°C (76°F) and lows of 12°C (54°F) in September, we recommend: Umbrella, Breathable clothing, Sunscreen (SPF 30+), Sun hat, Sunglasses. Comfortable walking shoes are essential.
Yes, September offers some of the best weather conditions in Gresham with comfortable temperatures and lower chances of rain.
The average UV index in Gresham during September is 5 (moderate). Sunscreen and sunglasses are recommended during midday hours.
Gresham gets approximately 13 hours of daylight per day in September, with around 10 hours of sunshine.
Snow is uncommon in Gresham during September based on 10-year climate averages.

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