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SunnyDays

ERA5 almanac comparison — 8 years of real data

Costa Rica — Guanacaste vs Hilton Head: weather in July

Essentially a tie in July: Costa Rica — Guanacaste is 16% clear historically, Hilton Head is 15% clear (8-year ERA5 average) — within the noise. Avg high 88°F vs 88°F. Pick based on flight time or price, not weather — the weather won't decide this one for you.

What you are reading: 8-year historical averages, not a forecast. Either destination can still surprise you this specific July. For the actual forecast right now, each destination links to its live page below.

Costa Rica — Guanacaste

Costa Rica

Clear days, July
16%
Sample size
n=248 days
Avg high
88°F
Early July (1st–15th)
9%
Late July (16th–end)
23%
Rain frequency
63% of days

Hilton Head

SC

Clear days, July
15%
Sample size
n=248 days
Avg high
88°F
Early July (1st–15th)
13%
Late July (16th–end)
16%
Rain frequency
64% of days
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Frequently asked

Is Costa Rica — Guanacaste or Hilton Head warmer in July?

Equally warm by day in July. Costa Rica — Guanacaste averages highs of 88°F (highs n=248 days); Hilton Head averages highs of 88°F (highs n=248 days) (ERA5 2018–2025). Historical averages, not a forecast.

Does it rain more in Costa Rica — Guanacaste or Hilton Head in July?

Days with measurable rain: Costa Rica — Guanacaste 63%, Hilton Head 64% (n=248 and n=248 days). ERA5 2018–2025; historical, not a forecast.

Which is sunnier in July, Costa Rica — Guanacaste or Hilton Head?

Essentially a tie in July: Costa Rica — Guanacaste is 16% clear historically, Hilton Head is 15% clear (8-year ERA5 average) — within the noise. Avg high 88°F vs 88°F. Pick based on flight time or price, not weather — the weather won't decide this one for you.

Compare Costa Rica — Guanacaste vs Hilton Head in another month

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 forecast for any destination is on its own page and may differ from the long-run average. Data from Open-Meteo.