Weather in Bar Harbor in August

Prime time. August is about as good as Bar Harbor gets. Highs average 22.4 °C, lows 14.8 °C, and rain falls on 12 days — nothing in the month is working against you.

August is the highest-scoring month of the twelve. The nearest rival is September, and the month at the other end of the year is December.

Rain on 12 days, 2 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: it never really gets hot: not one day in an average August reaches 30 °C. Across the twenty years measured, the hottest August day reached 30.5 °C and the coldest night fell to 9.3 °C, and the wettest single day dropped 90 mm — roughly 106% 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 173 mm against 24 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 85 mm average is a reasonable planning figure, not a promise.

Wind is light at 4.2 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 83%, high enough to notice on the warm days without dominating them.

How August sits in the year

Temperatures hold steady either side: 22.1 °C in July, 22.4 here, 19.3 in September. Nothing about the timing within the month matters much.

Daylight in August

14.1 hours of daylight, losing 1.3 hours across the month. That is between Bar Harbor's extremes of 15.5 and 8.9 hours, so days are long enough not to constrain the plan.

Sea temperature

The sea sits at about 15.1 °C in August — cold — a quick dip rather than a swim, and a wetsuit if you are in for longer. 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 Bar Harbor versus nearby

If Bar Harbor is one option among several, the nearby comparison is worth making. Sherbrooke is the weaker option in August — within a degree on temperature, 6 days more rain. Boston is close enough to be a coin toss — 5.6 °C warmer, 1 day less rain.

So: August is the answer for Bar Harbor. If it is booked out or priced out, September is the next best thing at 0 points behind, and December is the month to keep off the shortlist.

Every month in Bar Harbor

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