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SunnyDays

ERA5 almanac — 8 years of real data

Lanai in August

Lanai in August: 35% of days see measurable rain, 82°F average high, 26% of days historically clear (n=248, ERA5 2018–2025).

Lanai in August is historically a poor month for sun: only 26% of days clear across 8 years (n=248, avg high 82°F). January is the clearest month for Lanai 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 Lanai 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 August

Clear-sky percentage for Lanai in August, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period % Clear days Sample (n) Avg high
Early August
1st–15th		 31% n=120 82°F
Late August
16th–end		 21% n=128 82°F
Full month average 26% n=248 82°F

Sunshine & warmth in August

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 Lanai in August. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period Warm & sunny (≥72°F, >6 h sun) Sample (n)
Early August
1st–15th		 100% n=120
Late August
16th–end		 96% n=128
Full month average 98% n=248
12.6 h median sunshine per day 97% of days exceed 8 h sunshine 35% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 26%. Sunshine-based “warm & sunny”: 98%. The 72-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

Lanai is mostly overcast in August historically: only 26% of days are clear across 8 years (n=248), avg high 82°F. If you want sun in Lanai, January is historically much better. Most visitors this month will see more clouds than sun.

→ See all destinations in January — historically the best month for sun in Lanai.

Every month in Lanai

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

Historical clear-sky % for Lanai, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 32% n=248 All destinations →
February 19% n=226 All destinations →
March 20% n=248 All destinations →
April 14% n=240 All destinations →
May 17% n=248 All destinations →
June 20% n=240 All destinations →
July 20% n=248 All destinations →
August ← this page 26% n=248 All destinations →
September 16% n=240 All destinations →
October 20% n=248 All destinations →
November 31% n=240 All destinations →
December 27% n=248 All destinations →

Frequently asked

Does it rain in Lanai in August?

Sometimes. Lanai sees measurable rain on 35% of days in August historically (n=248 days, ERA5 2018–2025) — not frequent enough to plan around, but not negligible either.

Is Lanai good for sun in August?

Not usually. Lanai is historically overcast in August: only 26% of days are clear (avg high 82°F, n=248 days, ERA5 2018–2025). January is historically far better for sun here.

How Lanai compares in August

Head-to-head clear-sky comparisons against destinations travelers plausibly weigh against Lanai this month — same passport tier, similar flight distance, both sides from the same 8-year ERA5 record.

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.