Plano Texas WeatherPlano Texas weather can vary from hot and humid to cold and dewy. For those that are looking for the hottest month, July and August are the best months in Plano, Texas. Average temperatures during these months are in the mid to upper seventy degrees with relative humidity around fifty percent. With mild temperatures in the spring and summer and a cold front moving through in the fall, October is one of the colder months in Plano, Texas. The average temperature for the month of June is eighty degrees with a high of ninety-degree temperature on the day of a thunderstorm. With daytime temperatures reaching a daily high of sixty degrees, there is little need to dress for comfort. However, the evening temperature dipped just into the forty range with evening dew still making itself feels like ice on the window pane. July and August are when Plano, Texas weather really pops. There are not many days with temperatures higher than seventy degrees. But that does not mean that the air is excessively hot. Average temperature on the days of the four-week summer season is about fifty degrees with a high of ninety on the day of a thunderstorm. August sees a slight drop to eighty after the day of a high, but it quickly rises back up to the high of ninety again on the final day of the month. September is another extremely hot month in Plano. Average temperature on this day is around seventy degrees with a high of ninety. Over the course of the day, temperatures reach a daily high of near two hundred, then quickly drop below that figure a few hours later. Throughout the day, daytime temperatures are consistently around seventy degrees, but as nighttime temperatures dip below the seventy level, daytime temperatures start to increase. A little rain can make all the difference in a hot September day. October is the holiday season in Texas. Thanksgiving, Christmas and New Years are all popular times of the year in Texas. Many people buy new decorations and get their yards ready for the various holidays that are celebrated. The morning of Thanksgiving, temperatures will reach a high of around ninety with humidity hovering in the over one hundred degree range. After that, the day drops rapidly to around fifty, with a low around fifty at night. January is a very slow month in Plano Texas weather. Average temperature is around fifty degrees with a high around ninety. However, the day is much cooler than the evening hours. It starts out hot and humid, but quickly begins to cool down to around forty before the end of the day. If you are planning on visiting during the chillier days of January, you might consider staying overnight to avoid the chill. February is one of the best months in Plano Texas weather. Average temperature is around seventy with a high around ninety. The day is just a little cooler than the evening hours with cooler humidity around. A slight breeze starts off the day, but quickly changes as it begins to fade into a cool spell. March is considered a "normal" month in Plano Texas weather. Temps are consistently around seventy, with a high around ninety. Although there may be a few showers and a few storms, the temperature stays level for most of the day. If you visit at the beginning or end of this month, the temperature will rise to around eighty before decreasing a bit. If you visit any time of the month that has a cool spell lasting longer than three days, it will likely remain uncomfortably warm as temperatures drop in the afternoon.