Best Time to Dive Maryland
Across 32 Maryland dive sites with multi-year conditions history, conditions are broadly similar through the year — no single month stands out strongly. Average water temperature in the sample runs from about 5°C in January to 28°C in July. Typical seas range from 0.5 m to 0.8 m of significant wave height through the year. These figures are historical climatology computed from measured conditions — patterns, not a forecast or a guarantee.
Computed from our own conditions climatology — measured history, not brochure copy.
Which months are historically most favorable in Maryland?
| Month | Historically favorable days | Water temp | Typical seas |
|---|---|---|---|
| Jan | 98% | 5°C | 0.7 m |
| Feb | 99% | 5°C | 0.7 m |
| Mar | 98% | 8°C | 0.8 m |
| Apr | 100% | 13°C | 0.7 m |
| May | 100% | 18°C | 0.6 m |
| Jun | 100% | 23°C | 0.5 m |
| Jul | 100% | 28°C | 0.5 m |
| Aug | 100% | 27°C | 0.6 m |
| Sep | 99% | 24°C | 0.7 m |
| Oct | 100% | 19°C | 0.7 m |
| Nov | 100% | 14°C | 0.7 m |
| Dec | 99% | 7°C | 0.7 m |
% = share of sampled days scoring in the favorable band, median across 32 dive 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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