Best Time to Dive Northern Mariana Islands
Across 9 Northern Mariana Islands dive sites with multi-year conditions history, June historically shows the most favorable days — 88% of sampled days in the good band. The next-highest months are July (81%), August (76%) and May (75%). February historically shows the fewest favorable days (7% of sampled days). Average water temperature in the sample runs from about 28°C in February to 30°C in August. Typical seas range from 1.3 m to 2.3 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 Northern Mariana Islands?
| Month | Historically favorable days | Water temp | Typical seas |
|---|---|---|---|
| Jan | 11% | 28°C | 2.3 m |
| Feb | 7% | 28°C | 2.3 m |
| Mar | 32% | 28°C | 2.0 m |
| Apr | 58% | 28°C | 1.6 m |
| May | 75% | 29°C | 1.6 m |
| Jun | 88% | 29°C | 1.3 m |
| Jul | 81% | 30°C | 1.4 m |
| Aug | 76% | 30°C | 1.4 m |
| Sep | 72% | 30°C | 1.5 m |
| Oct | 41% | 30°C | 1.8 m |
| Nov | 26% | 29°C | 1.9 m |
| Dec | 10% | 29°C | 2.1 m |
% = share of sampled days scoring in the favorable band, median across 9 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 Micronesia & western Pacific region — not site-specific promises.
- Whale sharkDec–Jan
- Scalloped hammerheadFeb–Mar
- Humpback whaleJul–Oct
- Reef manta rayJun–Sep
- Tiger sharkyear-round
- Bull sharkyear-round
- Green sea turtleyear-round
Bars are Jan–Dec — months when sightings historically concentrate (GBIF occurrence records). Wildlife is never guaranteed.
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