Weather in Wellington in August

A hard month. August is a hard month in Wellington, and worth planning around. Highs sit at 11.9 °C and the day is short; this is an indoors-with-excursions month, not an outdoors-all-day one.

August ranks 11 of 12 — near the bottom of Wellington's year. February is the month that works, and the swing between the two is 36 points, which is a different holiday rather than a slightly better one.

This is persistent light rain rather than storms: 14 wet days but only 2 heavy ones. It rarely cancels anything outright, and it rarely fully clears either. A jacket beats an umbrella. Layers, and a genuinely waterproof outer — at 11.9 °C the difference between a good day and a miserable one is entirely down to what you are wearing.

What the averages hide

Averages flatten a month, and this one hides a few things: the day barely swings — 3 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest August day reached 15.2 °C and the coldest night fell to 4.1 °C, and the wettest single day dropped 48 mm — roughly 59% of the month's rain in one day.

August is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest August on record still delivered 122 mm against 30 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 82 mm average is a reasonable planning figure, not a promise.

Wind sits around 19.4 km/h — a steady breeze rather than a nuisance, and welcome on the warmer days, and humidity runs at 85%, which at 11.9 °C means damp rather than muggy — the kind of cold that gets into a coat and stays there.

How August sits in the year

Temperatures hold steady either side: 11.5 °C in July, 11.9 here, 13 in September. Nothing about the timing within the month matters much.

Daylight in August

10.4 hours of daylight, gaining 1.2 hours across the month. That is between Wellington's extremes of 15.1 and 9.2 hours, so days are long enough not to constrain the plan.

Sea temperature

The sea sits at about 11.6 °C in August — too cold to swim without a wetsuit. The sea peaks at 16.8 °C in February and bottoms out at 11.6 °C — water lags the air by a month or two, which is why the best swimming often comes after the best weather.

How busy it gets

Off season. The genuine off season: cheapest by a distance, with the caveat that some tours and restaurants close entirely.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

August in Wellington versus nearby

If Wellington is one option among several, the nearby comparison is worth making. Nelson is close enough to be a coin toss — within a degree on temperature, 1 day more rain. Palmerston North is close enough to be a coin toss — within a degree on temperature, 2 days more rain.

So: August is a compromise. February is 35 points better and is what Wellington is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in Wellington

See all twelve months in Wellington, or where else to go in August.