Weather in Bilbao in August

Prime time. August is about as good as Bilbao gets. Highs average 24.1 °C, lows 19.6 °C, and rain falls on 8 days — nothing in the month is working against you.

August ranks 2 of 12 in Bilbao. Only July scores clearly higher, and the difference is small enough to be settled by price rather than weather.

Rain on 8 days, 1 of them heavy. Enough to need a plan B, not enough to need a plan around it. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

Averages flatten a month, and this one hides a few things: the day barely swings — 4.5 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest August day reached 36.5 °C and the coldest night fell to 15.7 °C.

August is moderately variable: 12 mm in the driest year against 89 mm in the wettest, around an average of 36 mm. Roughly two Augusts in three land near that average, and the third does something else entirely.

Wind is light at 12.7 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 73%.

How August sits in the year

This is a turning point in the year — July and September sit on opposite sides of it, so the month contains the change rather than following it.

Daylight in August

14 hours of daylight, losing 1.3 hours across the month. That is between Bilbao's extremes of 15.4 and 9 hours, so days are long enough not to constrain the plan.

Sea temperature

The sea sits at about 21.9 °C in August — comfortable for a proper swim. This is the warmest the water gets all year.

How busy it gets

Peak season. Expect the highest prices of the year and to be booking well ahead.

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

August in Bilbao versus nearby

If Bilbao is one option among several, the nearby comparison is worth making. Gasteiz / Vitoria is close enough to be a coin toss — within a degree on temperature, 2 days more rain. Gijón is close enough to be a coin toss — within a degree on temperature, 1 day more rain.

So: August is effectively as good as it gets here — 0 points behind July, which is inside the margin where the weather stops being the deciding factor and price starts being it.

Every month in Bilbao

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