Verdict: Good month
Koh Samui Weather in July
July runs warm in Koh Samui, with daily highs around 28°C (82°F) and nights near 23°C (73°F). It's also the wet side of the calendar: rain falls on about 22 days, so build flexibility into plans. Overall, July is a solid month to visit Koh Samui.
Average high
28°C / 82°F
Average low
23°C / 73°F
Rain days
~22
Precipitation
125 mm
What to pack for Koh Samui in July
- Summer clothes, plus one light layer for air-con and evenings
- High-SPF sunscreen, sunglasses, and a refillable water bottle
- Rain gear is non-negotiable — expect rain on roughly 22 days
- Comfortable walking shoes — every guide on this site assumes you'll use them
July against the rest of the year
Warmest in Koh Samui: Apr (29°C / 84°F) · Coolest: Dec (25°C / 77°F) · Wettest: Oct (~27 rain days)
26°
22°
Jan
26°
22°
Feb
28°
23°
Mar
29°
24°
Apr
29°
24°
May
29°
24°
Jun
28°
23°
Jul
29°
23°
Aug
27°
23°
Sep
26°
22°
Oct
26°
22°
Nov
25°
22°
Dec
Daily highs / lows in °C · bars show rain days per month · ERA5 climate normals (2020–2024)