The average high temperature in the month of July is about 100°F (39°C). During the winter, temperatures will sometimes drop below freezing at night, but will warm up in the 50s°F (10s°C) during the day. St. George gets less than 8.5" (210 mm) of rain each year. The rain fall is spread pretty evenly throughout the year.  There isn't a rainy season.  However, in the sumers we sometimes get monsoon like rains that can bring localized but often intense thunderstorms from mid-July through mid-September.  Because the ground is usually so dry, it is impossible to soak up the water from the heavy intense rain falls, and can cause occasional flooding.  

In the last couple decades there has been a noticable wave of people relocating to the lower lying desert climates in this region of the country, including Phoenix Arizona and Las Vegas, Nevada- I would guess this is a result of baby boomers wanting to retire to mild winter locations where they don't have to deal with snow and can play and golf in the sun year round. St George offers all of that and more.  We have more attractive views, lower cost of living, lower crime rate, less traffic, and in general a unique community culture. Plus, our summer temperatures don't get quite as hot as those in Phoenix and Mesa, Arizona or Las Vegas, Nevada.

The great climate of St. George is often what attracts people to this area. The combination of warm dry winters and ow humidity summers draws new residents and tourists each year.  I especially hear this from retirees moving down from the Salt Lake City Area.  After living up there in the heavy snow inversions each year, they talk about having better health associated with the weather. You usually can see snow fall in St. George one or two days out of the year.  It is the kind of snow that doesn't even stick to the ground unless it falls in the coolest part of the night.  It is very rare to see snow on the ground past noon.  In fact, if snow ever sticks around that long you will see a parade of snow men throughout town because all the little kids get so excited to play in the snow like they have seen in the movies.  If you come from a snowy place, it is pretty funny to see a little kid scrape his entire front yard just to gather enough snow to make a 3' snow man!