does humidity affect how hot or cold it feels?
144194
Yes.. It's called heat index..\n--------------------------------------\nThe heat index (HI) or humidex is an index that combines air temperature and relative humidity to determine an apparent temperature — how hot it actually feels. The human body normally cools itself by perspiration, or sweating, in which the water in the sweat evaporates and carries heat away from the body. However, when the relative humidity is high, the evaporation rate of the water is reduced. This means heat is removed from the body at a lower rate, causing it to retain more heat than it would in dry air. Measurements have been taken based on subjective descriptions of how hot subjects feel for a given temperature and humidity, allowing an index to be made which corresponds a temperature and humidity combination to a higher temperature in dry air.\n\nAt high temperatures, the level of relative humidity needed to make the Heat Index higher than the actual temperature is lower than at cooler temperatures. For example, at 80 °F (approximately 27 °C), the heat index will agree with the actual temperature if the relative humidity is 45%, but at 110 °F (roughly 43 °C), any relative-humidity reading above 17% will make the Heat Index higher than 110 °F. Humidity is deemed not to raise the apparent temperature at all if the actual temperature is below approximately 68 °F (20 °C) — essentially the same temperature colder than which wind chill is thought to commence.\n\nAs relative humidity increases, however, first haze and ultimately thicker cloud cover must develop, reducing the amount of direct sunlight reaching the surface; thus there is an inverse relationship between maximum potential temperature and maximum potential relative humidity, therefore making, say, a simultaneous temperature of 120 °F (50 °C) and 90% relative humidity physically impossible. Because of this factor, it is believed that the highest heat-index reading actually attainable anywhere on Earth is approximately 160 °F (70 °C) in the shade that is 172 °F (78 °C) in the sun.\n\nA good example of the difference between heat index and true temperature would be comparing the climates of New Orleans, Louisiana and Bakersfield, California. New Orleans has lower heat temperatures due to being closer to the Gulf of Mexico, yet the city has a higher heat index because it is a humid heat. Likewise, while Bakersfield actually has hotter daytime temperatures, Bakersfield has a dry heat, so it doesn't feel as hot.\n\nSometimes the heat index and the wind chill factor are denoted collectively by the single terms "apparent temperature" or "relative outdoor temperature".\n\nA typical measurement in the United Kingdom in the hottest areas in the hottest type of weather generally has temperatures that can get above about 90 °F (32 °C) in the shade with 50% humidity which on the humidex chart is 104 °F (40 °C) in the shade and 119 °F (48 °C) in the sun. You should note that humidex and heat indexes are taken in the shade and not the sun; so extra care must be taken while in the sun! For the record, temperatures reached 101.3 °F (38.5 °C) in Kent in mid August 2003 which is the national record; assuming that this was 50% humidity; it would have a humidex of 126 °F (52 °C) in the shade and 140 °F (60 °C) in the sun. Of course in such extreme heat, the likelihood is that the humidity fell and the humidex was not quite that high.\n\nWARNING - Add approximately 15 °F (8 °C) to the heat index for measurements in direct sunshine.\n \nEffects of the heat index (shade values)\nFahrenheit Celsius Notes \n80–90 °F 27–32 °C Caution — fatigue is possible with prolonged exposure and activity \n90–105 °F 32–41 °C Extreme caution — sunstroke, heat cramps, and heat exhaustion are possible \n105–130 °F 41–54 °C Danger — sunstroke, heat cramps, and heat exhaustion are likely; heat stroke is possible \nover 130 °F over 54 °C Extreme danger —
246263
wind chill isn't actually a measure of how cold the air feels. a wind chill temperature is, rather, a calculation of how cold it would have to be to cause the same rate of heat loss from your skin if there were no wind blowing. wind chill approximates how cold it feels because the rate of heat loss corresponds with skin temperature, and skin temperature is what our nerves sense.\n\nthe chilling effect of wind comes from two sources:\n\n1. the disturbance of the insulating boundary layer of warm air over the skin\n\n2. the evaporative cooling effect of moisture loss from the skin.\n\nin practice, wind can also cause drafts within clothing and hence heat loss, but this effect is not considered in the chill factor calculation because of its obvious variability. \n\nnote: you cannot cool to a temperature much lower than that of the wind, but you can cool faster to that temperature. depending on the humidity, it is possible to drop below the air temperature by a few degrees.\n\nclick on link by source for more info, you'll also find a wind chill formula on their page.
934169
No, rain cannot give you a cold.  What it can do, however, is lower your defenses making your body more vulnerable to infection by the virus which actually causes the cold.  This is especially true when the rain is accompanied by lower temperatures and windy conditions.
444733
Unsaturated.  The air can still take on more humidity.  When the dew point is at or above the air temperature, you have fog or other percipitation.
803179
Changes in air pressure and possibly humidity.  Your body turns into a barometer.
774374
It's because there is typically less humidity in the air in the winter.  Humidity refers to moisture in the air and dampness on the surfaces of objects, and this moisture helps to dissipate or equalize the static charge.
220189
Yes deedee. Your body becomes tense and cramped. It is a form of anxiety and tension building up. Your body is reacting to the cold weather by building up warmth within you. It will release any excess fluids but it will also generate heat as you get up to go to the bathroom.\n\nLove\nBaby Doll
284283
Heat isn't a problem for computer equipment until it gets above ~160°F. Whether it's turned off or not doesn't make much difference to the silicon. Humidity, on the other hand, can make a mess of a computer quite fast.
1016033
Its probably the humidity. I have friends from africa who tell me that when its over 100 degrees you don't even sweat.
502375
Your fever is your body fighting the infection. It raises it's temperature to kill the bacteria. When you feel cold, it's your body reacting to your fever trying to cool you down by giving you chills so you won't be uncomfortabley hot.
591876
Warm air holds more water vapor than cold air.  That is why a clothes dryer uses heated air to draw the moisture from the clothes.  It is also why when warm moist air meets cold air it results in precipitation.
350316
A reading of 100 percent relative humidity means that the air is totally saturated with water vapor and cannot hold any more, creating the possibility of rain. This doesn't mean that the relative humidity must be 100 percent in order for it to rain -- it must be 100 percent where the clouds are forming, but the relative humidity near the ground could be much less.\n\nHumans are very sensitive to humidity, as the skin relies on the air to get rid of moisture. The process of sweating is your body's attempt to keep cool and maintain its current temperature. If the air is at 100-percent relative humidity, sweat will not evaporate into the air. As a result, we feel much hotter than the actual temperature when the relative humidity is high. If the relative humidity is low, we can feel much cooler than the actual temperature because our sweat evaporates easily, cooling us off.
676222
as the air cools it cannot hold the same amount of moisture as the warm daytime air can. as the result, the moisture is released and we feel this as humidity.\n\nhumidity is the amount of moisture in the air relative to the temperature. 30% humidity means that at that temperature, the air contains 30% of the total amount of moisture it can hold. as the temperature drops, the air cant hold as much moisture.
868843
It's harder for your body to cool off when it's hot because the difference in temperature is not as large as when it is cool.  Put another way, the cool air on a cool day, regardless of the relative humidity, helps to cool you off.
140386
Hot or cold is relative to your body temperature. Something less will feel blah, cool, or cold depending on how much less. Vice versa for hot. The 'starting point' for hot or cold can be different for each person, or even for the same person, like if you just worked out, everything will seem a little warmer for a while.
106276
I have to disagree with bobpegoh.  Wind chill DOES change the actual physical temperature of anything that has moisture. Nor is it a matter of simple heat transfer, although that can come into play.\n\nThis is the basic answer to your question - your skin has moisture but the outside of the pipe (where the wind hits) is dry.  If on a windy day you were to put something that absorbs water easily outside, you would feel the item cool in the wind.\n\nThe chilling effect is caused by evaporation (see the link below).  The physics is complicated, but basically when the humidity is below a certain point, water will evaporate and use some of the heat energy in your skin to accomplish that.\n\nPractical exercise.  Take a small wash rag and get it wet, squeezing out excess water.  Swing the rag  in a circle as fast as you can for a minute or so.  When you stop, the rag should be noticeably cooler than when it started.\n\nHow much of the heat energy depends on the relative humidity* - as the humidity gets lower, it takes less energy for the water to evaporate, so it doesn't cool down as much.  When the RH gets higher, evaporation will take more energy until the point where there is too much humidity and the water stops evaporating altogether.\n\nRelative humidity and evaporation are a critical part of our bodies ability to regulat heat.  Our bodies actually generate quite a bit of heat just on normal stuff like breathing and circulating blood, and without a way to cool down, our bodies would overheat.  One way we do this is to take advantage of evaporative cooling by sweating.  Wind increases the cooling and blows warmed, humid air away from our body.  \n\nThis is why weather people talk about "heat index" - when the temperature and  humidity get high, our bodies can't dump the excess heat without help.  The heat index is a comparison of how easily our body can dump heat at the current temperature and humidity vs. the current temperature and a standardized humidity.
582102
Air is denser the lower you go on the earth, due to gravity pullin gthe air down. As you move up, there is more "room" for the air to expand. Air temp is just the measure of the net kinetic energy of the molecules of air. The faster and more there are, the hotter it is. therefore, as the air expands as it moves up into the atmosphere, it cools. On top of a mountain, there is less molecules actually hitting your skin, so it feels very cold.