Despite a relatively cool July —the mean July temperature was actually cooler than the mean June Temperature, both here in Lawrenceville and in Atlanta— it looks like August is going to be our hottest month of the year.

The short range, medium range, and long range forecasts are all calling for warmer than normal temperatures, and it looks like we may not get much rain to help out, at least until the middle of the month.

Temperatures will be approaching the 100 degree mark all this week in North Georgia. To make things worse, we’ll likely be seeing high dew points as well. That means that the humidity will be approaching the unbearable range. Take a look at the forecast dew points in Georgia for 2 PM Thursday:

If this forecast validates, we’ll see the heat index above 105 degrees, the danger level, several times this week.

Ultimately, it’s the moisture in the air that determines how we feel when we go outside. Although relative humidity is the measurement most people use to measure moisture content, the dew point temperature can provide a better measure of how uncomfortable conditions are. When the dew point rises to near 70 or above, most people are unlikely to want to be outside for very long.

The heat index also measures the apparent temperature. For more detail, take a look at this table showing the relationship between relative humidity, temperature, heat index, and dew point.

The reversal from the cool and wet July conditions to the hot and dry conditions for August isn’t going to do much to help the drought conditions in Georgia. Over the last month, the drought levels in Georgia haven’t changed very much. While the rain has kept lawns green in the short term, we will see a quick return to brown lawns without more rainfall.

As I’ve said before, tropical weather will probably be the key to breaking the drought. Despite the relatively quiet season so far, the latest forecast by Dr. Gray at Colorado State University is still calling for an above average hurricane season. The researchers are predicting 15 tropical storms for the season, down 2 from their May forecast, and eight hurricanes, down from nine in May. There’s also an above average chance of a major hurricane striking the US coast.

The dewpoint on Saturday measured 78.6 degrees late in the morning, which is the highest measured so far this year. With the temperature around 85 degrees at the time, the heat index felt like it was 95. By 2 PM, the temperature had risen to 92, and with the dew point still at 76, the heat index stood at 104.

That’s still not the highest heat index for the year, which was 106 on July 27th. On that day, we had the warmest temperature of the year, at 97, however the humidity was lower.

Look for one more day of unpleasantly hot and humid weather on Sunday before things begin to back off a bit going into the latter part of the week. While the cold front that could have brought a taste of fall will stay to our north, we’ll enjoy a few days with highs in the mid 80s.

The forecast for next weekend and into the beginning of the last week of August is for a chance of cooler than normal temperatures, and below normal precipitation. An extended forecast into Labor Day weekend calls for slightly above-normal temperatures, but still below normal rainfall.

Gwinnett is preparing for some of the warmest weather of the season over the next few days, with heat indexes possibly rising to the point where the Weather Service will post an advisory for people to stay indoors.

Today’s high temperature of 92.9 here at my weather station marks the third straight day of above 90 degree temperatures. Fortunately, a front moving into the area from the north has lowered the dewpoint considerably from what we’ve seen in previous days. Today’s mid afternoon dewpoint was six degrees lower than it was at this time yesterday, meaning a heat index of 95 instead of yesterday’s 105, which is the high for the summer.

Sunday and Monday are likely to be warmer than today, and while the effects of the ridge will likely keep rain away, it will weaken, and give us higher humidity and more discomfort. By Thursday, we could see some thundershowers, and this wave of heat could be history by Friday.

While temperatures in the 90s are an expected part of life in Georgia, that isn’t the case for much of the rest of the country, which is also suffering from extreme heat. Here are some temperatures, measured close to 6 PM. The first number is the temperature, while the second is the heat index:

Memphis - 94 (108)
Carroll, Iowa - 97 (119)
Des Moines - 97 (113)
Ainsworth, Nebraska - 104 (101)
Kansas City - 98 (106)
Brookings, SD 97 (112)
St. Louis - 96 (117)
Boise - 89 (85)
Denver - 93 (89)

It’s interesting to note the fact that for the far west, the heat index is lower than the actual temperature. That’s because the relative humidity is in the teens. For example in Denver, the temperature is 93 and the dewpoint is 40, with 16 percent relative humidity.

Meanwhile, as far as tropical weather goes, Franklin seems to be heading into the Eastern Atlantic, and doesn’t appear to be a threat, although there is a chance it could curve west again, and threaten the Carolinas. Tropical Depression Seven has been declared in the Gulf of Mexico, and is likely to develop into tropical storm Gert before it makes landfall in central Mexico sometime Sunday night.