There's no bad time to dive Hurghada. The Egyptian Red Sea is one of the few destinations in the world that supports recreational diving every month of the year. But the months differ in ways that matter to specific divers, and the marketing copy on most diving websites flattens those differences into nothing.
This is what each season is actually like, from the perspective of someone who runs the boat year-round.
Summer (June to September)
Water temperature 27-29 °C. Visibility 25-30 m, sometimes 35 m on flat-calm days. 3 mm wetsuit or shorty is enough. Air temperature 32-38 °C, which is the headline issue · the heat above water is more demanding than the heat below it.
This is whale shark season. Sightings around Hurghada are sporadic but real · 8-12 per season recently across roughly 200 long-transit boat days. The longer-transit days where the captain runs the boat to the wilder northern reefs are statistically the best whale-shark chances.
Downsides: peak tourist season, more boats on the popular reefs, hotels and flights at peak prices. Heat stroke risk above water is real · we put extra shade on the boat in July-August and the briefings get shorter.
Autumn (October to November)
Water 25-27 °C. Visibility holds at 25 m. The crowds drop noticeably from mid-October. This is the second peak for hammerhead sightings (the first is May, but autumn is more reliable). Eagle rays are at peak frequency on the deeper wall sites.
This is the season I'd recommend to a diver booking their first Hurghada trip · enough warmth to be comfortable, enough visibility to see far, enough biology to be interesting, fewer crowds.
Winter (December to February)
Water 21-23 °C, occasionally dropping to 20 °C in February. 5-7 mm wetsuit, plus a hood if you feel the cold. Visibility variable · 18-25 m on calm days, drops to 12-15 m after a winter storm has stirred the silt.
Wind matters in winter. The captain may cut the longer-transit days when the forecast is over force 4. Trip rotation tends toward the closer sheltered reefs. Days with calm forecast still happen reliably, but you might lose a day or two to weather across a week-long trip.
Upside: fewest crowds of the year. Christmas guests get a near-private boat experience. Costs are lowest. The reefs themselves are the same · they don't go anywhere because of the season.
Spring (March to May)
Water 22-26 °C, climbing through the season. 5 mm wetsuit early, 3 mm by May. Visibility builds back up to 25-30 m by April.
May is the start of hammerhead season at the deeper wall sites. The water has warmed enough that the wetsuit isn't an issue, the visibility has cleaned up, and the summer crowds haven't arrived yet. May is the operator's quiet favourite · same diving as summer, half the boats.
Practical recommendation
If you want crowds-free diving: late October, November, March, May.
If you want whale sharks: late August, September.
If you want hammerheads: May or October.
If you want guaranteed warmth and the most predictable conditions: July, August (with the heat caveat).
If budget is the deciding factor: January, February.
Whatever you pick, the reefs themselves are constant · the difference is conditions, not biology.