ERA5 almanac — 8 years of real data

Mazatlán in July

Mazatlán in July: 39% of days see measurable rain, 89°F average high, 33% of days historically clear (n=248, ERA5 2018–2025).

Mazatlán in July is historically a poor month for sun: only 33% of days clear across 8 years (n=248, avg high 89°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 Mazatlán 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 July

Clear-sky percentage for Mazatlán in July, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period	% Clear days	Sample (n)	Avg high
Early July 1st–15th	39%	n=120	89°F
Late July 16th–end	28%	n=128	89°F
Full month average	33%	n=248	89°F

Sunshine & warmth in July

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 Mazatlán in July. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period	Warm & sunny (≥72°F, >6 h sun)	Sample (n)
Early July 1st–15th	98%	n=120
Late July 16th–end	98%	n=128
Full month average	98%	n=248

11.4 h median sunshine per day 94% of days exceed 8 h sunshine 39% of days see ≥ 1 mm rain — rain is not hidden

Comparison (old vs new): WMO-code “clear” bar: 33%. Sunshine-based “warm & sunny”: 98%. The 65-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

Mazatlán is mostly overcast in July historically: only 33% of days are clear across 8 years (n=248), avg high 89°F. Most visitors this month will see more clouds than sun.

Every month in Mazatlán

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

Historical clear-sky % for Mazatlán, all months, ERA5 2018–2025.
Month	% Clear	Sample (n)
January	91%	n=248	All destinations →
February	85%	n=226	All destinations →
March	98%	n=248	All destinations →
April	98%	n=240	All destinations →
May	97%	n=248	All destinations →
June	62%	n=240	All destinations →
July ← this page	33%	n=248	All destinations →
August	16%	n=248	All destinations →
September	15%	n=240	All destinations →
October	58%	n=248	All destinations →
November	90%	n=240	All destinations →
December	93%	n=248	All destinations →

Frequently asked

Does it rain in Mazatlán in July?

Sometimes. Mazatlán sees measurable rain on 39% of days in July historically (n=248 days, ERA5 2018–2025) — not frequent enough to plan around, but not negligible either.

Is Mazatlán good for sun in July?

It's mixed. Mazatlán in July is clear on 33% of days historically (avg high 89°F, n=248 days, ERA5 2018–2025) — the outcome varies year to year.

How Mazatlán compares in July

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

→ Mazatlán vs Memphis in July — Memphis is 33% clear historically
→ Mazatlán vs Shenandoah Valley in July — Shenandoah Valley is 34% clear historically
→ Mazatlán vs Toronto in July — Toronto is 34% clear historically

→ Mazatlán live forecast — this week’s actual 7-day weather, not historical
→ Best destinations in July — all destinations ranked by July clear-sky %
→ All destinations
→ Raw data (JSON) — buckets, n, source

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.