Indiana is no longer participating in the notion that Earth is a Class M planet. This is not completely surprising, as Indiana elected long ago to ignore daylight saving time, and in certain parts of the state, electricity.
During summer in Indiana, the air is not breatheable. Today it is 98F with the heat index. Last night it was even higher. On my way home from campus I slipped in a streak of melted asphalt that hasn't dried since it was poured three days ago, sprained my ankle, and acquired asphalt grafts in my palms. This morning I went my Kroger's, limping through scorchingly hot and gellid air convecting off of the pavement. I half-expected to see a mirage at the midpoint, maybe David Duchovny on a lawn chair under a striped umbrella, a cooler full of peach Snapple at his side.
Once inside, I realized that a year's worth of parking-lot bubble gum splotches had boiled their way out of petrification and onto the soles of my red sneakers, melting into the plastic.
The streets are still eerily empty this evening. The heat prickles and shrivels my skin, and my eyeballs feel like raisins. My window unit air conditioner is making a room-sized micro-climates with light rain. I put an umbrella upside-down under it to catch the water, which the cat licks like a popsicle.
Desperate for solace, I tried to read an online weather report for more than the temperature. Will it rain? Will it cool? When? How? The answer lies in the numbers next to humidity, dewpoint, and barometric pressure. Here are the short explanations I've discovered for these numbers (long explanations can be found in the header links):
Humidity
Humidity refers to water vapor in the air; that is water in the form of an invisible gas. Relative humidity is the amount of water vapor in the air compared with the amount of vapor needed to make the air saturated at the air's current temperature. Humidity is represented as a percentage (i.e., 30% saturated), etc. Humidity rises with heat because warmer air can "hold" more water.
Dewpoint
When the air can no longer "hold" all of the water vapor in it, the vapor begins condensing into ordinary, liquid water. If the air is in the sky, the vapor condenses into cloud drops. If the air is right above the ground the vapor condenses to make fog in the air, and dew on the grass. Dew point is given as the temperature at which local air has to cool to for the water vapor to begin condensing, forming clouds andor fog andor dew.
Barometric Pressure
Barometric pressure is the weight of atmospheric pressure at the Earth's surface. Air in a high pressure area compresses and warms as it descends. The warming inhibits the formation of clouds, meaning the sky is normally sunny in high-pressure areas. In general, falling air pressure means that clouds and precipitation are more likely.
Falling barometric pressure here means that the air won't be kept quite as warm as it descends, so the night air might actually have a chance at falling to the dewpoint and getting some of this moisture out of the air. Add an incoming cold front to the mix, and as I read it, that means it might not be so bad tomorrow.
But just in case it is, I'll be next to the air conditioner, with my umbrella and a good book.
| 
