We have a popular saying here in Maine: if you don’t like the weather, wait five minutes. The weather is one of the more challenging aspects of sailing in Maine, but don’t let that deter you! We’ve put together a list of helpful weather tips for sailing in Maine.
Prevailing Winds
In the summer, the prevailing winds are out of the Southwest, and if high pressure is in place you will almost always see the wind out of the south or southwest. This prevailing wind can make it easy to arrive in Maine from points south, but can make heading south in the late summer or fall difficult.
When cold fronts come through, the wind will typically swing to the Northeast and the Southeast before returning to the Southwest. On the bright side, Maine has many beautiful and very well-protected anchorages!
Afternoon Onshore Breeze
Wind speeds on the Maine coast typically run through a daily cycle. The mornings are generally calm with very light winds, but as the land mass heats up an onshore breeze with a southerly component will typically bring winds around 10-15 knots in the afternoon. Winds will then calm again at night.
Cold ocean temperatures typically keep the air out to sea cool. When land heats up, that warm air will rise and cool air from the ocean will rush in to fill that space. It provides a nice cooling onshore breeze, and fantastic afternoon sailing conditions. If you prefer to sail over motor, you can treat yourself to slow morning coffee because you likely won’t see the breeze start to pick up until 11 or so in the morning.
Temperatures
Maine summers on the coast are made for layering clothes. You may start the morning in full foulies and a winter hat, and by the afternoon be jumping in the water to cool off. Typically, the islands will be around 10 degrees cooler than the mainland harbors, so if you see a heat wave in the forecast, it’s best to head for the outer islands.
When a front comes and winds come from the north, temperatures will drop, but sometimes the humidity will not! This can make even 60 degrees feel very cold, so be sure to have some warm clothes ready!
Also, a quick note about water temperatures. Be safe when considering swimming while in Maine. The water temperatures will only break into the 60s(F) in Late July and August, so before that cold water shock is a real risk. Consider your health, swimming abilities and conditions before jumping in, even if the air temps are hot!
Fog
It’s impossible to have a conversation about Maine weather for sailors without talking about fog.
The majority of fog in Maine summers is advection fog, which forms when warm, humid air moves over the cold Gulf of Maine waters. Maine is particularly good at creating fog because the prevailing wind direction (SW) brings in warm and wet air, our 9-11ft tides keep our coastal waters cold, and our hilly coastline contributes to fog-friendly air movement.
All in all, you can expect fog to be a regular occurrence. In some years, we’ve seen it as much as 10-12 days in a row. But all is not lost. Generally, the increased afternoon onshore breeze will also break up the fog, so by the time you have enough wind to sail, you likely will have a clearer view as well.
For this reason, we highly recommend planning most of your sailing for the afternoons. But if you must travel in the fog do so carefully!
Swell and Wind Waves
Swell is usually caused by weather far out to sea, and especially in August and September, you will see some heavy swell kicked up by the Atlantic hurricanes. Without major storms in the Atlantic, the swell will be light. When the swell is larger, you may experience some wrap-around in seemingly protected anchorages in the outer islands.
One of the many upsides to having over 4,600 islands along the coast is that there isn’t a ton of fetch for wind waves. Many popular sailing areas like Casco Bay, Penobscot Bay and the Stonington area are very well protected even from a southerly breeze. You will likely be surprised that 10-15 knots of wind will barely ripple. Those afternoon onshore breezes paired with this protection make for some champagne sailing!
Thunderstorms
Unlike many parts of the East Coast, Maine doesn’t see thunderstorms every afternoon. But they do happen, and will typically roll in from a westerly direction. Keep an eye on the sky! We also recommend getting a weather app that will notify you of incoming storms and keeping your VHF on during the day to receive any special weather notices.
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