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SunnyDays

ERA5 almanac — 8 years of real data

Austin in April

Austin in April is historically a poor month for sun: only 35% of days clear across 8 years (n=240, avg high 80°F). 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 Austin 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 April

Clear-sky percentage for Austin in April, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period % Clear days Sample (n) Avg high
Early April
1st–15th		 39% n=120 80°F
Late April
16th–end		 31% n=120 80°F
Full month average 35% n=240 80°F

Sunshine & warmth in April

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 Austin in April. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period Warm & sunny (≥72°F, >6 h sun) Sample (n)
Early April
1st–15th		 72% n=120
Late April
16th–end		 70% n=120
Full month average 71% n=240
9.6 h median sunshine per day 64% of days exceed 8 h sunshine 42% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 35%. Sunshine-based “warm & sunny”: 71%. The 36-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

Austin is mostly overcast in April historically: only 35% of days are clear across 8 years (n=240), avg high 80°F. Most visitors this month will see more clouds than sun.

Every month in Austin

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

Historical clear-sky % for Austin, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 4% n=248 All destinations →
February 15% n=226 All destinations →
March 26% n=248 All destinations →
April ← this page 35% n=240 All destinations →
May 27% n=248 All destinations →
June 32% n=240 All destinations →
July 47% n=248 All destinations →
August 46% n=248 All destinations →
September 41% n=240 All destinations →
October 48% n=248 All destinations →
November 25% n=240 All destinations →
December 11% n=248 All destinations →

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.