Pinnacles National Park has a Mediterranean climate with hot and dry summers, and mild winters with moderate precipitation. The park is several miles inland from the Pacific Ocean, without the moderating effects that coastal regions of California such as the San Francisco Bay Area experience. Hence, a wider variation in seasonal temperatures can be expected in the local area. On July or August day, daytime temperatures over 100° F are not uncommon, while overnight subfreezing winter temperatures are not uncommon. Spring and fall are typically the most pleasant weather for hiking and visiting the park. Hiking Smart in Pinnacles Weather.