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Hurricane season

Hurricane season is the portion of the year when tropical cyclones are most likely to form in a given ocean basin.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 27, 2026|2 min read| Fact-checked

Hurricane season is the portion of the year when tropical cyclones are most likely to form in a given ocean basin. In the Atlantic, the official season runs from June 1 to November 30, with peak activity typically in early to mid-September. Storms can still occur outside the official dates.

Definition

Hurricane season is an informal and official climatological term for the period when atmospheric and ocean conditions are most favourable for tropical cyclone formation in a basin. The exact dates differ by ocean region.

Atlantic hurricane season

In the Atlantic basin, the official season runs from June 1 to November 30. NOAA notes that the historical peak is around September 10, and most activity occurs from mid-August to mid-October.

Other basins

The eastern Pacific basin has an official season from May 15 to November 30. Other basins have different seasonal windows based on local climate patterns and water temperatures.

Why storms peak in late summer

Hurricanes are more likely when ocean waters are warm, wind shear is relatively low, and humid air is abundant. These conditions are most common in late summer and early autumn in the Atlantic.

Canadian relevance

Hurricanes and post-tropical storms can affect Atlantic Canada, and Canadian emergency guidance describes hurricane season in eastern Canada as running from June to November.

Key facts

  • The Atlantic hurricane season is officially June 1 to November 30.
  • Atlantic activity usually peaks around September 10, with most activity between mid-August and mid-October.
  • Storms can form outside the official season dates.
  • Canada’s Atlantic coast can be affected during the Atlantic hurricane season, and eastern Canada’s hurricane season is commonly described as June to November.
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Canadian context

Atlantic Canada is exposed to hurricanes and post-tropical remnants during the Atlantic hurricane season, and the Canadian Red Cross describes hurricane season in eastern Canada as June to November.[12]

Frequently asked questions

What is hurricane season?
It is the part of the year when tropical cyclones are most likely to form in a region, especially in the Atlantic and eastern Pacific basins.
When is Atlantic hurricane season?
The official Atlantic hurricane season runs from June 1 to November 30.
When is the peak of Atlantic hurricane season?
NOAA identifies the climatological peak as around September 10, with the busiest period usually from mid-August to mid-October.
Can hurricanes happen outside hurricane season?
Yes. NOAA states that tropical cyclone activity sometimes occurs before or after the official dates.
Why does hurricane season exist?
It reflects when ocean temperatures, humidity, and wind conditions are most favourable for tropical cyclone development.

References

  1. NOAA — https://www.noaa.gov/tropical-cyclone-climatology
    Supports: Official Atlantic and eastern Pacific hurricane season dates; Atlantic peak timing; storms can occur outside official dates.
  2. NOAA Ocean Service — https://oceanservice.noaa.gov/facts/hurricane.html
    Supports: Hurricane season begins June 1 and ends November 30; storms can occur outside that timeframe.
  3. Scientific American — https://www.scientificamerican.com/article/hurricane-season-explained-and-what-to-expect-in-2026/
    Supports: Physical conditions contributing to hurricane formation, including warm waters, low wind shear, and humid air.
  4. Canadian Red Cross — https://www.redcross.ca/how-we-help/emergencies-and-disasters-in-canada/types-of-emergencies/hurricanes/hurricanes-information-facts
    Supports: Hurricane season in eastern Canada runs from June to November.