Best Time to Dive Ontario
Across 50 Ontario dive sites with multi-year conditions history, July historically shows the most favorable days — 64% of sampled days in the good band.
Computed from our own conditions climatology — measured history, not brochure copy. Historical patterns, never a forecast or a guarantee.
Month by month
| Month | Historically favorable days | Water temp | Typical seas |
|---|---|---|---|
| Jan | 11% | — | — |
| Feb | 21% | — | — |
| Mar | 16% | — | — |
| Apr | 24% | — | — |
| May | 35% | — | — |
| Jun | 41% | — | — |
| Jul | 64% | — | — |
| Aug | 42% | — | — |
| Sep | 52% | — | — |
| Oct | 22% | — | — |
| Nov | 10% | — | — |
| Dec | 11% | — | — |
% = share of sampled days scoring in the favorable band, median across 50 sites with at least two years of history. Ringed = historical peak.
How does this compare worldwide? The Most Reliable Diving Months on Earth ranks 61 countries by the same measure.
Marine life seasons
Sighting patterns across the wider US & Canada — Atlantic coast region — not site-specific promises.
- Scalloped hammerheadAugust
- Great white sharkAug–Sep
- Giant oceanic manta rayJul–Sep
- OrcaMay–Aug
- Humpback whaleJun–Aug
Bars are Jan–Dec — months when sightings historically concentrate (GBIF occurrence records). Wildlife is never guaranteed.
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