I created this as a thorough but concise description of the weather in Phoenix. Comments? Suggestions? Corrections?
Typical weather in Phoenix by month (average high and low at the end):
January
High 65 to 70 degrees, low around 40 to 45 degrees. It rains about three to seven days in the month, with about 20 sunny days. On days it rains, it is usually a little cooler, about 55 to 60 degrees for the high. About once every three years, one night it might dip down to about freezing. We get about one inch of rain on average in the winter months each month. Winters in Phoenix are described as feeling like the spring back East. 66/40
February
High 70 degrees, low around 45 degrees. It rains about three to five days in the month, with about 22 sunny days. Trees that lose their leaves in the winter start budding again, so this is the start of our spring. 71/43
March
Highs around 75 degrees, low around 45 to 50 degrees. It rains about three to four days in the month, with about 25 sunny days. 76/48
April
High 75 to 85 degrees, low around 50 to 55 degrees. It rains about one or two days per month, with about 25 sunny days. The real warm up starts in this month, and the wildflowers bloom all over the desert if we had a rainy winter. The winter storms usually stop in April. 82/54
May
High 85 to 95 degrees, low around 55 to 60 degrees. It rarely rains in this month, and usually there will be no more rain until the summer monsoons kick off in July. Phoenix typically has about 30 sunny days in May and June. The first 100 degree day appears towards the end of the month. Most residents start running their AC and swamp cooler units in May, and June is the first real month with massive AC use on a daily basis. 92/61
June
Highs 95 to 105 degrees, lows around 65 to 75 degrees. It virtually never rains in June and steadily gets hotter as the month progresses. Giant high pressure systems park near the four corners area of Arizona, New Mexico, Colorado and Utah, thus ensuring our long hot summers. Swamp coolers work best this month, because of the low humidity (often around 5 to 10%) and no rain. 102/68
July
High 100 to 115 degrees, low around 75 to 85 degrees. July is the first month that residents really starting bitching about the heat. As the month progresses, 110 degree days start appearing. As moisture moves in from the Gulf of Mexico, the humidity levels spike, and this usually signals the start of the monsoon thunderstorm season. By the end of July, every third day will have towering thunderclouds, with blowing wind, spotty rain and dust, and every fifth day will have a massive thunderstorm with brief but torrential downpours. In these rain events, temps will drop rapidly from 105 to 110 down to about 75 or 85 degrees. Many Phoenicians will drive up north for an hour or two to escape to the cool pine mountain forests of northern Arizona (summer highs in the 70s and 80s) near Payson, Prescott and Flagstaff, while others flee to the California coast near San Diego and elsewhere, just five hours west by car. Phoenix usually gets about one inch of rain per month in the summer monsoon season, which usually runs from mid-July to early September. 106/76
August
Highs 100 to 110 degrees, lows around 75 to 80 degrees. By August, the temps start to cool a little bit, and the monsoon thunderstorms will rage on about five to eight days per month. Phoenix hunkers down for the long haul this month, and backyard swimming pools get heavy use. About 70% of the homes in Phoenix have swimming pools, the highest percentage in the U.S. 104/73
September
High 95 to 105 degrees, lows around 70 to 80 degrees. Monsoon thunderstorms start dwindling this month, and by the second week, usually stop. The 100+ degree dry heat returns with a vengeance for a week or two, before a noticeable cooling trend begins by the end of the month. 97/67
October
Highs 85 to 100 degrees, lows around 60 to 75 degrees. October is usually a dry month, and Phoenicians celebrate the last 100 degree day in this month as the noticeable cooling trend accelerates. Once more, doors and windows are thrown open and pools get less use as Phoenicians return from summer vacations and get out more. By Halloween, a chill is in the air as temperatures continue to drop. 88/54
November
Highs 65 to 80 degrees, lows around 45 to 60 degrees. It usually does not rain much in November, but by the end of the month, the gentle winter storm track begins to establish. On the few days it does rain, it is usually a little cooler, about 60 degrees for the high. A few trees start to change color in this month, as the temps continue to drop rapidly. 73/44
December
High 65 to 75 degrees, low around 40 to 45 degrees. Trees lose all of their leaves through December. It rains about three to seven days in the month, with about 20 sunny days. On days it rains, it is usually a little cooler, about 55 to 60 degrees for the high. About once every three years, one night it might dip down to about freezing. We get about one inch of rain on average in the winter months each month. 69/41
--don