Weather in Hamilton in September 2025
- September is usually the hottest month of the year in Hamilton;
Average weather
Average temperature in Hamilton in September
The expected average maximum temperature in September is +81°F with a maximum of +82°F and a minimum of +75°F.
The average maximum temperature goes down 25% by the end of the month, compared with the beginning of the month, from +82°F to +81°F.
Is Hamilton warm or cold in September?
Hamilton is typically warm in September.
Maximum temperatures go up compared to the previous month from +81°F to +81°F. The minimum temperature also goes down from +79°F to +77°F.
It’s generally warm, but pack a long-sleeve shirt for evenings.
September is the hottest month in Hamilton, here is the comparison with other months:
Climate in Hamilton in September
| August | September | October | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +81°F | +81°F | +77°F | ||||
| Min. temperature | ||||||
| +72°F | +68°F | +63°F | ||||
| Max. temperature | ||||||
| +90°F | +88°F | +84°F | ||||
| Rainfall | ||||||
| 121 mm | 122 mm | 146 mm | ||||
| Wind | ||||||
| 4 m/s | 4 m/s | 5 m/s | ||||
| Humidity | ||||||
| 80% | 78% | 75% | ||||
| Air pressure | ||||||
| 1018 HPa | 1016 HPa | 1016 HPa | ||||
| Sunny days | ||||||
| 3 | 2 | 1 | ||||
| Cloudy days | ||||||
| 5 | 7 | 9 | ||||
| Rainy days | ||||||
| 21 | 21 | 21 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
September weather is still as ok as in August. The temperature levels stay the same in the area of +81°F for average maximum temperature during the day. Prepare for more rain. Average rainfall goes from 121 mm to 122 mm. It feels drier, as humidity decreases from 80% to 78%. The average wind speed doesn’t change much during September, staying around 4 m/s. The days becoming less sunny, going from 3 sunny days in August to 2 in September.
October brings much the same weather, it remains ok.
Wind
The average wind speed is 5 m/s getting up to 15 m/s which is quite strong. The wind will cause branches to move and ground debris to fly around.
The average wind speed in Hamilton is gradually decreasing during September, going from 8 m/s to 3 m/s over the course of the month.
Rain
How was the weather last September in Hamilton?
Climate Change Over the Years
The climate in Hamilton in September has not changed that much over the last 43 years.
The average temperature was the lowest in 1981 (+71°F) and the highest in 2019 (+76°F). The driest year was 1979 with only 854 mm of rainfall, and the wettest year was 2023 with 1671 mm.
FAQ
Is September a good time to visit Hamilton?
Can you sunbathe in Hamilton in September?
Is Hamilton rainy in September?
Is it sunny in Hamilton in September?
Monthly weather in Hamilton
Source of the data
For this page, we’ve looked at the typical weather in Hamilton, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.
