Weather
Iowa is located in what is called the North Temperate Zone, where there can be considerable seasonal--and even daily--variation in the weather. The coldest temperature on record for Iowa City was –32F (-36C) on February 13, 1905; the hottest recorded temperature, according to the KCRG web site, was 109F (43C) on July 14, 1936.
Many foreign students and scholars come from areas with less variation, so they have to learn to adjust their wardrobes for the changes that can happen here. People living in Iowa are advised to listen to radio or television weather reports each day, to get notice of expected conditions and changes. "
Severe Weather
Severe weather in various forms--heavy snows, high winds, ice storms, thunderstorms, high heat and humidity, and tornadoes--can come at various times of the year. Being prepared with appropriate clothing, and in some cases an umbrella, can reduce your discomfort and make you safer during harsh weather.
Thunderstorms
A thunderstorm contains lightning and thunder and most often heavy rain. When thunderstorms are severe, they contain any one or more of the following three weather conditions:
- Hail that is 3/4 of an inch or greater in diameter
- Winds 58 miles per hour or greater
- Tornadoes
Thunderstorm Warning - What to do
- Get storm updates from a local radio station. Make sure a battery-powered radio is nearby.
- Stay indoors.
- Do not turn on the television.
- Lightning can cause power surges. Unplug all appliances before the storm hits.
- Avoid using the phone. Telephone lines can conduct electricity.
- Metal pipes also conduct electricity. Stay away from faucets, sinks, and bathtubs.
- Close the blinds and shades of your window, then keep away from them.
Tornados
A tornado is a violently rotating column of air extending between, and in contact with, a cloud and the surface of the earth.
Tornadoes are generally spawned by thunderstorms, though they have been known to occur without the presence of lightning. The stronger tornadoes attain an awe-inspiring intensity, with wind speeds that exceed 200 mph (322 km/hr) and in extreme cases may approach 300 mph (483 km/hr). Multiple tornadoes can emerge from the same storm.
Tornado Warning - What to do
When a tornado warning has been issued, you may have very little time to prepare.
- Get inside immediately.
- Make sure you have a portable radio for information updates from a local radio station.
- Seek shelter in the lowest level of the building you are in (basement or storm cellar). If there is no basement, go to an inner hallway, a smaller inner room, or a closet. Keep away from all windows. Do not enter a mobile/trailer home, find shelter elsewhere.
- Cover your head and eyes with a blanket or jacket to protect against flying debris and broken glass.
- Do not go outside until officials say it is safe.
Floods
Floods occur when rainfall occurs so intensely that the ground cannot absorb it and/or streams and rivers cannot carry the runoff away within their banks. Flash floods are ones where flooding develops very rapidly, within a few minutes to a few hours. This is usually in association with sustained heavy thunderstorm rain over the area.
Sometimes the flash flooding occurs as a wall of water coming down streams in low-precipitation areas because of torrential rain over adjacent hilly areas upstream. Slower-developing flooding (sometimes called "main stem flooding") occurs on larger streams and rivers from large areas of sustained heavy rain and/or snowmelt. The breaking of ice or debris jams or levees in these situations can also result in local flash flooding.
Flash Flood Warning - What to do
- There many be no time for a warning to be issued. You may have only seconds to escape. It could be a life-and-death decision for you and your family.
- If you suspect a flash flood is about to happen immediately climb to higher ground.
- Remember, it does not have to be raining for a flash flood to occur. Some of the most dangerous floods originate many miles away.
Heat Waves
Heat waves can include the following:
- A spell of sweltering humidity, which reaches levels commonly associated with moist tropical regions. The stress on the body can be exacerbated when atmospheric conditions cause pollutants to be trapped near the ground.
- An excessively dry condition, in which strong winds and blowing dust can worsen the situation.
- A rise in the heat index: the body's perception of the "apparent" temperature based on both the air's real temperature and the amount of moisture present in the air. Humidity and mugginess makes the temperature seem higher than it is. In high humidity, an 85°F (29°C) day may be perceived as 95°F (35°C).
During a Heat Wave - What to do
- If you must go out, wear lightweight, light-colored clothing to reflect the sun's energy.
- Slow down, avoid strenuous outdoor activity. If you must engage in strenuous activity, do it during the coolest part of the day, between 4 am and 7 am.
- Cover all exposed skin with a high SPF sun screen, and wear a wide brimmed hat to protect your face and head.
- Drink plenty of fluids.
Winter Storms
Winter storms can include blizzard conditions, freezing rain, sleet, dangerous combinations of temperatures and wind. And winter storms can be deceiving; even a small amount of precipitation can cause problems in areas where snow is an unusual occurrence.
Winter Storm Warning - What to do
- Get storm updates from The Weather Channel or the local TV or radio station.
- Stay indoors.
- If you must go out, wear several layers of clothing. Layers will keep you warmer than a single heavy coat.
- Wear gloves and a hat to keep from losing body heat.
- Keep dry to prevent a loss of body heat.
- Watch for signs of frostbite: a loss of feeling and a white, pale appearance in fingers, toes, nose or ear lobes.
- Watch for signs of hypothermia: uncontrollable shivering, slow speech, memory lapses, frequent stumbling, drowsiness, and exhaustion.
Resources
For additional information on weather conditions and preparing for different storms, please visit: