Skip to main content
SunnyDays

ERA5 almanac — 8 years of real data

Phuket in May

Phuket in May: 85% of days see measurable rain, 87°F average high, 5% of days historically clear (n=248, ERA5 2018–2025).

Phuket in May is historically a poor month for sun: only 5% of days clear across 8 years (n=248, avg high 87°F). February is the clearest month for Phuket historically. Historical average, not a forecast.

What you are reading: 8-year historical averages from the ERA5 reanalysis, not a forecast. A month that is historically 90% clear can still be overcast on your specific trip. For this week’s actual forecast, see the live Phuket page. Both can be true at once: “historically strong in this month; this particular week is not.” We label which is which.

Early vs. Late May

Clear-sky percentage for Phuket in May, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period % Clear days Sample (n) Avg high
Early May
1st–15th		 3% n=120 87°F
Late May
16th–end		 7% n=128 87°F
Full month average 5% n=248 87°F

Sunshine & warmth in May

A second measure using actual sunshine hours (ERA5 sunshine_duration), not the daily weather code. A Lowcountry day with 12 hours of sun and a 25-minute afternoon storm is counted below as a warm, sunny day — because it was. How we define this.

Sunshine-based metrics for Phuket in May. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period Warm & sunny (≥72°F, >6 h sun) Sample (n)
Early May
1st–15th		 88% n=120
Late May
16th–end		 88% n=128
Full month average 88% n=248
10.2 h median sunshine per day 78% of days exceed 8 h sunshine 85% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 5%. Sunshine-based “warm & sunny”: 88%. The 83-point gap is from brief afternoon convective storms that stamp the whole day as “rain” in the WMO code but leave the bulk of the sunshine untouched.

Bottom line

Phuket is a poor choice for sun in May: just 5% of days clear historically (n=248). February is the historically strongest month for sun here. The 8-year record is consistent — this is not a fluke bad stretch.

→ See all destinations in February — historically the best month for sun in Phuket.

Every month in Phuket

Compare across all months with data. Numbers are historical clear-sky %.

Historical clear-sky % for Phuket, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 25% n=248 All destinations →
February 41% n=226 All destinations →
March 29% n=248 All destinations →
April 8% n=240 All destinations →
May ← this page 5% n=248 All destinations →
June 8% n=240 All destinations →
July 8% n=248 All destinations →
August 6% n=248 All destinations →
September 3% n=240 All destinations →
October 2% n=248 All destinations →
November 4% n=240 All destinations →
December 16% n=248 All destinations →

Frequently asked

Does it rain in Phuket in May?

Yes, frequently. In Phuket, 85% of days in May see measurable rain, based on 8 years of ERA5 historical data (n=248 days, 2018–2025). This is a historical average, not a forecast.

Is Phuket good for sun in May?

Not usually. Phuket is historically overcast in May: only 5% of days are clear (avg high 87°F, n=248 days, ERA5 2018–2025). February is historically far better for sun here.

All percentages are historical averages from the ERA5 reanalysis via Open-Meteo, 8 full years (2018–2025). “Clear” means avg high ≥ 72 °F, precipitation < 1 mm, and a non-precipitation weather code. This is history, not a forecast. The live 7-day outlook for any destination is on its own page and may differ from the long-run average. Data from Open-Meteo.