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150 years of climate data
No guesswork. Every month rated using 150 years of daily weather records from Charlottetown Airport — the longest continuous climate record in Atlantic Canada. Pick a month to see exactly what to expect.
Interactive weather tool
Based on Environment Canada normals for Charlottetown Airport, 1874–2024.
Selected month
Avg high
-0.5°C
Low: -8.5°C
Sun hours/day
2.9h
Daily average
Rain days
54%
of days see rain
Good day odds
68%
chance of dry day
Swimming in December
No — water is too cold
Year at a glance
January
-3.5°C high · 52% rain days
February
-3.1°C high · 48% rain days
March
1.4°C high · 44% rain days
April
8.2°C high · 42% rain days
May
15.3°C high · 38% rain days
June
20.8°C high · 36% rain days
July
24.2°C high · 34% rain days
August
23.9°C high · 36% rain days
September
19°C high · 38% rain days
October
12.3°C high · 44% rain days
November
5.6°C high · 52% rain days
December
-0.5°C high · 54% rain days
Season by season
July & August
Peak season on PEI runs July through mid-August. Average highs sit at 24°C with Gulf water temperatures reaching 20–22°C — the warmest swimming in Atlantic Canada. Rain falls on roughly 1-in-3 days but rarely lasts long. Expect full tourist infrastructure: every restaurant open, every trail groomed, every campsite booked.
Why come now
Watch out for
Local tip
The last two weeks of July are statistically the best stretch of weather PEI gets all year — high pressure dominates, winds are calm, and the Gulf hits peak temperature.
September & October
September is PEI's best-kept secret. Crowds drop sharply after Labour Day, prices fall 30–40%, and the weather stays genuinely good — average highs of 19°C, the lowest rain frequency of any shoulder month, and Gulf water still warm enough to swim from the first week. October turns golden with fall foliage and is ideal for cycling.
Why come now
Watch out for
Local tip
The first two weeks of September offer nearly identical weather to August at a fraction of the cost and crowd. If you can only go once, go then.
May & June
PEI springs are cool, green, and unhurried. May averages 15°C with wildflowers blooming across the island. June warms quickly — by mid-month you're hitting 20°C regularly, the tourist season begins, and everything opens up. The island feels fresh and uncrowded in a way summer never does.
Why come now
Watch out for
Local tip
Late June is an underrated sweet spot — warm enough for most activities, Gulf water approaching swimmable, and the summer crowds haven't arrived yet.
December to March
PEI winter is real winter — average highs below zero from December through February, regular snowfall, and the Northumberland Strait freezing along the shores. It's not a tourist destination in the conventional sense. But Charlottetown is a genuine small city with good restaurants, the Confederation Centre of the Arts, and an unhurried pace that regulars love.
Why come now
Watch out for
Local tip
If you're visiting in winter, base yourself in Charlottetown — the city has real infrastructure year-round. Drive out to the national park on a clear day after a snowfall.
Quick comparison
| Month | High | Low | Rain days | Rating |
|---|---|---|---|---|
| 🥶January | -3.5°C | -12.5°C | 52% | Off-season |
| ❄️February | -3.1°C | -12.9°C | 48% | Off-season |
| 🌬️March | 1.4°C | -7.8°C | 44% | Shoulder |
| 🌱April | 8.2°C | -0.7°C | 42% | Good |
| 🌸May | 15.3°C | 5.3°C | 38% | Great |
| ☀️June | 20.8°C | 10.7°C | 36% | Peak |
| 🏖️July | 24.2°C | 14.5°C | 34% | Peak |
| 🌊August | 23.9°C | 14.3°C | 36% | Peak |
| 🍂September | 19°C | 9.7°C | 38% | Great |
| 🍁October | 12.3°C | 4°C | 44% | Good |
| 🌧️November | 5.6°C | -1.6°C | 52% | Shoulder |
| 🌨️December | -0.5°C | -8.5°C | 54% | Off-season |
Source: Environment Canada · Charlottetown Airport · 1874–2024 normals (150 years of records)
Frequently asked questions
Every answer is based on 150 years of records — not guesses.
July is statistically PEI's best month for weather — average highs of 24.2°C, the lowest rain frequency of the year (34% of days), and Gulf water temperatures reaching 20–22°C. The last two weeks of July consistently deliver the longest runs of settled, sunny weather based on 150 years of records from Charlottetown Airport.
August is excellent. Average highs are 23.9°C — nearly identical to July — and the Gulf water is at its warmest of the year (20–22°C). Rain falls on about 36% of days but showers are typically short. The main downside is that peak-season crowds and prices are still in full effect through mid-August before tapering off after Labour Day.
September is arguably PEI's best-kept secret. Average highs drop to 19°C but the Gulf water is still 17–19°C — perfectly swimmable. Crowds drop sharply after Labour Day, accommodation prices fall 30–40%, and the island gets a beautiful golden quality as fall sets in. Rain frequency stays low (38% of days), making it one of the drier months of the year.
PEI summers are warm but not extreme. Average highs reach 24.2°C in July and 23.9°C in August. The record high ever recorded at Charlottetown Airport is 36.7°C (1935). Heat waves occasionally push temperatures into the low 30s for a few days at a time, but sustained heat is uncommon — ocean breezes moderate the temperature across the island.
PEI gets rain year-round but not excessively. July and August have the lowest rain frequency — around 34–36% of days. Even in the wetter months (November, December), rain rarely falls all day. The island gets approximately 1,170mm of precipitation annually, spread fairly evenly. If you're visiting in summer, expect a short shower every 2–3 days on average.
Yes — the Gulf of St. Lawrence is the warmest ocean water in Atlantic Canada. Gulf water temperatures typically reach 20–22°C by late July and remain swimmable (17–19°C) through September. The north shore (Cavendish, Stanhope) warms faster than the south shore due to shallower water. In early June, water is still around 12–14°C — cold for most swimmers.
June is a transitional month. Early June averages around 17–18°C with cool nights. By late June, highs regularly reach 20–22°C. Rain falls on about 36% of days — similar to July. The Gulf water is still 12–16°C in June, which most people find too cold for extended swimming. June is excellent for cycling, hiking, and exploring without summer crowds.
October is a beautiful shoulder month. Average highs drop from 19°C (early October) to around 10°C by month's end. Fall foliage peaks across the island, making the Confederation Trail particularly scenic. Rain frequency rises slightly (44% of days). Most tourist businesses have closed or reduced hours. It's ideal for those who want fall scenery without the PEI summer experience.
PEI winters are genuinely cold. Average highs range from -3.5°C (January) to 1.4°C (March). The record low ever recorded is -37.2°C in 1875. Snow is regular from December through March, and the Northumberland Strait partially freezes along shore. Wind chill frequently makes temperatures feel -20°C or colder. Charlottetown remains fully operational year-round.
The spring lobster season on PEI typically runs from late April to late June, and a shorter fall season runs from August to October. July is the sweet spot where both summer weather and freshly caught lobster overlap — many visitors plan their trip around a lobster dinner at one of the island's waterfront restaurants or lobster suppers.
Plan your trip
Historical averages tell you what to expect. Live conditions tell you what's happening right now. OpenAir Atlantic checks weather, air quality, UV, and tides at 16 PEI locations every 10 minutes.