This post may contain affiliate links. If you purchase through them, I may earn a small commission at no extra cost to you. Thanks for supporting our small business.
Puerto Peñasco, known to American visitors as Rocky Point, sits at the northeast corner of the Sea of Cortez in Mexico’s Sonora state, about 100 km (62 mi) south of the Arizona border. The climate is hot desert (Köppen BWh), which means 300-plus sunny days a year and only about 86 mm (3.4 in) of rain annually. Sea temperatures swing from a cool 16°C (61°F) in February to a bath-warm 29°C (84°F) in August, so the water is swimmable almost all year.
Puerto Peñasco Weather in Winter (December to February)
Winter is the coolest stretch of the year but still mild by North American standards. January is the coldest month, averaging 15.4°C (60°F), with daytime highs around 20°C (68°F) and overnight lows near 9°C (48°F). December is the wettest month of the year at roughly 15 mm (0.6 in) of rain. The Sea of Cortez cools to 16 to 19°C (61 to 66°F), too cold for long swims for most people but fine for wetsuit snorkeling and fishing. Bring a light jacket for evenings on the Old Port malecón.
Puerto Peñasco Weather in Spring (March to May)
Spring is the most comfortable season. Highs climb from 23°C (73°F) in March to 29°C (84°F) in May, with lows between 12°C (54°F) and 17°C (63°F). April and May are the driest months, often recording under 2 mm of rain, and the sea warms from 18°C (64°F) to 22°C (72°F) by May. This is the sweet spot for beach days without the summer heat, which is why so many visitors pair a spring trip with whale watching and dune riding.
Puerto Peñasco Weather in Summer (June to September)
Summer is genuinely hot. July and August both peak at 35°C (95°F), and overnight lows stay at 26 to 27°C (79 to 81°F). June is nearly rainless at 0.7 mm, but the North American monsoon brings brief afternoon downpours in August (around 20 mm) and September (around 15 mm). August is the most humid month at about 64% relative humidity. The sea reaches its warmest, 27 to 29°C (81 to 84°F), which makes swimming feel like a bath. If you visit in summer, do outdoor activities before 11:00 and check the best time to visit guide for shade strategies.
Puerto Peñasco Weather in Fall (October to November)
Fall cools off fast and stays dry. October highs average 29°C (84°F) and November drops to 24°C (75°F), with lows of 18°C (64°F) and 13°C (55°F). The sea holds warmth at 26°C (79°F) in October before slipping to 22°C (72°F) in November. October is one of the two best months of the year for weather, and it is when the town hosts its biggest event, the Rocky Point Rally. If you drive in for it, review the travel tips and FAQ for the border crossing.
Puerto Peñasco Weather by Month: Temperature and Rainfall Table
| Month | Avg High | Avg Low | Rain (mm) | Sea Temp |
|---|---|---|---|---|
| January | 20°C (68°F) | 9°C (48°F) | 9 | 17°C (63°F) |
| February | 21°C (70°F) | 10°C (50°F) | 6 | 16°C (61°F) |
| March | 23°C (73°F) | 12°C (54°F) | 4 | 18°C (64°F) |
| April | 26°C (79°F) | 14°C (57°F) | 2 | 20°C (68°F) |
| May | 29°C (84°F) | 17°C (63°F) | 1 | 22°C (72°F) |
| June | 33°C (91°F) | 21°C (70°F) | 1 | 25°C (77°F) |
| July | 35°C (95°F) | 26°C (79°F) | 10 | 27°C (81°F) |
| August | 35°C (95°F) | 27°C (81°F) | 20 | 29°C (84°F) |
| September | 33°C (91°F) | 24°C (75°F) | 15 | 28°C (82°F) |
| October | 29°C (84°F) | 18°C (64°F) | 7 | 26°C (79°F) |
| November | 24°C (75°F) | 13°C (55°F) | 6 | 22°C (72°F) |
| December | 20°C (68°F) | 9°C (48°F) | 15 | 19°C (66°F) |
For lodging near the water, see our where to stay in Puerto Peñasco guide.
