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SunnyDays

ERA5 almanac — 8 years of real data

Dallas in June

Dallas in June is historically a poor month for sun: only 38% of days clear across 8 years (n=240, avg high 91°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 Dallas 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 June

Clear-sky percentage for Dallas in June, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period % Clear days Sample (n) Avg high
Early June
1st–15th		 36% n=120 91°F
Late June
16th–end		 39% n=120 91°F
Full month average 38% n=240 91°F

Sunshine & warmth in June

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 Dallas in June. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period Warm & sunny (≥72°F, >6 h sun) Sample (n)
Early June
1st–15th		 92% n=120
Late June
16th–end		 97% n=120
Full month average 94% n=240
12.6 h median sunshine per day 88% of days exceed 8 h sunshine 40% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 38%. Sunshine-based “warm & sunny”: 94%. The 56-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

Dallas is mostly overcast in June historically: only 38% of days are clear across 8 years (n=240), avg high 91°F. Most visitors this month will see more clouds than sun.

Every month in Dallas

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

Historical clear-sky % for Dallas, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 3% n=248 All destinations →
February 11% n=226 All destinations →
March 23% n=248 All destinations →
April 33% n=240 All destinations →
May 36% n=248 All destinations →
June ← this page 38% n=240 All destinations →
July 47% n=248 All destinations →
August 54% n=248 All destinations →
September 48% n=240 All destinations →
October 49% n=248 All destinations →
November 21% n=240 All destinations →
December 9% 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.