Selfoss Weather in September
September in Selfoss averages 12°C (54°F) during the day and 7°C (45°F) at night. It is the wettest month of the year, with 177 mm (7 in) of rainfall on average, so waterproof gear is a must.
Rainfall in Selfoss in September
It records the year's peak rainfall, often coming down quite heavily. We recommend bringing a poncho, which will keep you dry. The climate data from previous years indicates about 18 days of rain, averaging 177 mm (7 in) for the month. Rain falls regularly this month and can be quite heavy when it does. Showers can be substantial, so waterproof gear is a good idea.
Temperature in Selfoss in September
In September, Selfoss sees moderate temperatures, with highs of 12°C (54°F). Nights drop to around 7°C (45°F). Temperatures can feel cooler in the morning and evening, so layering is often the best approach. Nights drop to 7°C (45°F). Cold nights like these are actually great for sleeping well, as long as you have a warm enough duvet.
Sunshine in Selfoss in September
With about 121 hours of sunshine, the area enjoys a nice balance of sun and overcast, creating a pleasant environment.If you prefer dry days with pleasant temperatures, September may not be the ideal month to visit Selfoss. Our weather planner can help you explore destinations with more pleasant weather conditions.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Iceland, check out our Selfoss's climate page.
Selfoss Temperature in September
Min Temperature
7°C (45°F)
Max Temperature
12°C (54°F)
Chance of Rain
59%
Precipitation
177 mm (7 in)
Rainy days
18 days
Humidity
79% *
Sunshine
121 hours *
Percentage Sunshine
30% *
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Selfoss typically stay consistent throughout September, with daily highs averaging around 12°C (54°F). Nights are cold, with lows typically ranging from 4°C (39°F) to 8°C (46°F).
Average temperatures in September
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather for Selfoss in September
Browse day-by-day weather records for Selfoss spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Selfoss historical weather extremes in September
Based on 49 years of weather observations (1976-2025), these are the most extreme conditions recorded in Selfoss.
- The warmest day in September was on September 2, 2006, with a maximum of 18°C (64°F).
- On September 23, 2005, Selfoss saw its coldest September day with temperatures maxing out at 3°C (37°F).
- The coldest night in September in Selfoss was on September 27, 1995, with a minimum of -4°C (25°F).
- The wettest September day on record brought 47 mm (1.9 in) of precipitation to Selfoss (September 12, 2007).
Best Places in Iceland in September
Find out more about the weather in Iceland and which places have the best travel conditions in this month. See all of Iceland in September →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in Selfoss in September
The weather can swing between comfortable and chilly in September, so flexibility is key. Pack a variety of tops, at least one warm layer, and both shorts and long pants. This gives you options no matter what the day brings. It's going to pour! Pack a good poncho and prepare for very wet conditions. It won't hurt to bring your sunglasses along, as you'll see some sunny periods.What To Do in Selfoss in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Iceland, check out our Selfoss's climate page.
Temperature Rainfall Sunshine Humidity
See the full Selfoss climate overview or explore weather in Iceland.
