Short answer: 90°F is playable with preparation — hydrate before and during, tee off early, and ride if walking 18 would push you. Above 95°F with high humidity, heat illness becomes a genuine risk and early-morning or twilight golf is the smart play.
| Temperature | Playability | Notes |
|---|---|---|
| 80–90°F | Warm | Comfortable for most with water and sun protection. |
| 90–95°F | Hot | Hydration plan required. Morning tee times strongly preferred. |
| 95–100°F | Very hot | Heat exhaustion risk, especially with humidity. Ride, don't walk. |
| 100°F+ | Extreme | Dawn patrol or skip. Our score applies heavy penalties here. |
Dry 95°F in Phoenix plays very differently from humid 90°F in Houston. When the heat index (temperature + humidity) passes ~100°F, sweat stops evaporating efficiently and your core temperature climbs. Check the heat index, not just the thermometer.
Mild good news: hot air is less dense, adding roughly 1–2 yards per 10°F of carry. Firm, baked fairways add roll too. The challenge is the golfer, not the ball.