Portsmouth Weather in September

Portsmouth in September averages 28°C (82°F) during the day and 19°C (66°F) at night. This is the wettest month of the year.

Rainfall in Portsmouth in September

Prepare for the heaviest rain of the year this month, which often comes in heavy showers. A poncho is a smart choice to stay dry. Historically, approximately 10 days this month are expected to have rain, averaging 170 mm (6.7 in). The rain this month tends to fall in heavier spells rather than light drizzle. When it rains, showers can be significant.

Temperature in Portsmouth in September

If you're visiting Portsmouth in September, expect highs of 28°C (82°F) and overnight lows around 19°C (66°F). Overall, the month follows a fairly predictable daily temperature pattern. Nights cool down to 19°C (66°F), so a light jacket or extra layer is useful once the sun goes down. On the plus side, the cooler nights make for comfortable sleeping conditions.

Sunshine in Portsmouth in September

There are approximately 230 hours of sunshine this month, resulting in mostly clear days.

If your ideal day consists of dry skies and pleasant temperatures, April typically offers the best circumstances for Portsmouth.