San Diego enjoys mild, subtropical, sunny weather throughout the year. Average monthly temperatures range from about 57 °Fahrenheit (14 °C) in January to 72 °Fahrenheit (22 °C) in July, although late summer and early autumn are typically the hottest times of the year. The average annual daily temperature is 70.5 °Fahrenheit. Snow and ice are virtually nonexistent in the wintertime, typically occurring inland from the coast.
San Diego’s position in Southern California allows for an exposure to a diverse range of weather within driving distance. For example, on a single day in April you could see three different climates. Start the day off with a morning stroll on the beach. Next, drive 45 minutes east to a dry desert region. Finally, continue north east for another hour and a half and you’ll reach snow-capped mountains.
Rainfall is strongly concentrated in the cooler half of the year, particularly the months December through March, although precipitation is lower than any other part of the U.S. West Coast. The summer months are virtually rainless. Rainfall is highly variable from year to year and from month to month and thunderstorms and hurricanes are very rare. Measurable snowfall has never occurred in downtown San Diego. Light amounts of snow have occurred in higher locations within the city limits, according to the national weather service climatological summary.
Las Vegas
Las Vegas is in a desert state and so the climate is that of an arid desert. Summer are hot, winters are mild and there is abundant sunshine all year round with very little rainfall.
Temperatures can reach up to 90° Fahrenheit (mid 30's° Celsius) in the months of May, June and September and can exceed 100°F (39°C) in July and August. Humidity is relatively low often being under 10%.
Winters are usually cool and windy and the majority of Las Vegas's rainfall, an average of 4.49 inches falls in January to March. Winter temperatures are normally around 60°F (16°C). Rain showers occur less frequently in Spring and Autumn but through July to Septemeber the Mexican Monsoon brings enough moisture into the South West to cause afternoon thunderstorms.