Why does water always feel colder than the air? Even if it says it is the same temperature on a thermometer?
457072
The cooling effect is caused by the air or water removing heat from your skin. The water being much more dense, can and does remove much more heat than air. If the water and your hand are stationary, your hand will eventually heat up the water touching your hand and then it will feel warmer. As soon as you move your hand the cooler water will be felt again. This is where Chill Factor can be explained also.  As the wind speed increases the fresher cold air removes more heat from the skin making it "feel" colder.
596282
Because theres so much water thats constantly moving that the sun can't warm it all up. The ocean is so deep, and that water is about 30 degrees (yes farenheit, which doesnt freeze because of the salt in it) that it continusoly gets mixed up and remains a constant tempertature that seems cold to us. =)
312206
Water continues to become more dense as it cools until just above the freezing point.  I can't remember the exact temperature off-hand, but I believe it is very near 33.5 to 34 degrees Fahrenheit.  \n\nBelow that water begins to expand and once it has frozen, its volume increases approximately 10%...that's why ice floats...less dense than the water it came from!  Cool, huh?
541181
See this answer.  Dig into the citations for the reference articles in them.  The second also has references.\n\nHot freezes faster in many cases, given certain controls such as same amount of water, same size and shape container, standard pressure etc.  There  is at least one experiment showing that water at 90 degrees C will freeze quicker than water at 18 degrees C.  This is significant since one side is quite close to boiling and the other is basically room temperature.\n\nIf you are not a high school student, I would look up linear programming ( a branch of algebra not computer science) and develop a sensitivity analysis to determine the impact of various effects.
556811
Thermometer Measures the Actual temperature, by the implementation of a device or mercury's reaction to the degrees.\n\nWind chill is a FACTOR- as it blows across our skin, the temperature is PERCIEVED to be colder, as our skin is being Cooled faster- the wind blows our body warmth away.\n\nWind chill factor is Calculated, Not Measured.
419356
I will take a stab at it.  I am guessing it is because water has more degrees of freedom.  In the liquid there is also rotational degrees of freedom to absorb energy that the solid ice does not have.\n\nTo Neil, the formulas are for heat capacity and have nothing to do with the way something is heated, only the amount of energy that it takes.\n\nNor does it have anything to do with Newton's law of cooling.
62870
Cold Water. - Most of the time. \nI have tried and tested this before (Tap Water). The hot water normaly takes about 10 minutes longer. When using Tempratures like 30 degrees and 70 degrees this will begin to vary and warm water might start freezing faster than cold water. \n\nWarm water can in fact sometimes freeze faster than Cold water but it very much depends on the conditions.\n\nWhat you are thinking of is the Mpemba effect. This could be due to a number of factors including but not limited to Evaporation (less water needed to be freezed), Dissolved Gasses and Convection.\n\nFor a lengthy but thorough explanation see the link below.\n(Very reliable references) \nhttp://math.ucr.edu/home/baez/physics/General/hot_water.html
912336
it heats up if  you go down for a long way,\nwith water it sinks to 4 degrees then if it gets colder it rises ,dont ask me why ,it is just that way.\nWater does not always follow the rule \n\nground temperature is the coldest at the surface ,in cold weather,\nthan below it is constant for a long way \nafter a few miles it will heat up.
1054158
I think the key words in your question are "at room temperature".  See, room temperature is less than body temperature.  Heat energy wants to go from a higher temp region to a lower temp region.  But, water absorbs heat energy at a faster rate than air.  So, the cooling feeling (or transfer of heat away from your body into the surrounding medium) is greater in water than in air.  Now, turn on a fan and have more air, thus more cooling medium moving over you taking heat away and it will feel cooler even inf the air is at the same room temperature.
868477
water freezes at 32 degrees Fahrenheit, and 0 degrees Celsius\n\nthe colder the faster
53097
well, ice is solid, water is liquid, and air is gas, and the potential energy increases as the stages change.  in other words, air is the warmest, water next, and ice last.  air being the warmest will warm up the ice faster and therefore melt it quicker.\n\nthe only reason that i can see why it'd be in water is if there's been a sudden change in temperature and the water is still warm but the air is cooler (cold front after a week of mid 60s or 70s weather).
903913
The frozen one feels heavier because of the more solid (for lack of a better word) weight distribution. Did you try comparing weight by holding the bottle upright in the palm of your hand? That should give you a better relative idea. The weight is the same, in theory (assuming each bottle had exactly the same amount of water to begin with, the same amount of trapped air, and were both completely air-tight (all of which are unlikely)).
259573
Ice water? If you have ice and water together they keep each other at the same temp. 0 degrees C. If you add salt this will make the ice melt at a lower temp. which will cause the water to be lower temp. also, giving you a below 0 C reading.
271556
In addition to the fact that at 4 degrees celcius, water has an absolute density of EXACTLY 1 g/cc, at 0 degrees, it is in equilibrium with its solid phase (ice) which has a density of LESS than 1 g/cc due to its open cage like crystal structure. So, its exact density at 0 degrees is impossible to standardise.
158964
Water retains temperature more than air, so the oceans stay warm in winter and cool in summer. They cool air currents that blow around the continents.
555489
Water is a liquid and until the water get near freezing, water as it cools becomes more dense and sinks. Warmer water moves to the surface. For ice to form on a lake the temperate of all the water in the lake has to get below 39 degree F. \n\nLand on the surface may get colder but in temperate climates at certain depth the soil is always above freezing.
933014
All decent explanations so far; I hope I can add to what has already been posted.\n\nLiquid and Ice most definitely can exist at the same temperature and Ice can be and often does get colder than 0C.\n \nFirst of all the Triple Point of water is the pressure and temperature at which Ice, Liquid Water and Water Vapor exist at the same time in equilibrium.  Vapor is the right word, not steam although you can argue that the only time that Water Vapor and Steam are the same thing is at a very low pressure.  The Triple point of water only happens at a near perfect vacuum, 0.0063 ATM to be precise.\n\nAdding Salt to water will lower the freezing point, but then it isn't water anymore, it's salt water.  Even so, Liquid Salt Water and Ice Salt Water can also exist at the same place and time at the same temperature, slightly below 0C.  But let's stick to water.\n\nIce can easily be lower than 0 degrees.  Consider a bucket of water, liquid water sitting outside and the air temperature is -10C.  Little by Little, as the liquid reaches 0.0098 C, liquid starts to become ice.  The ice crystals form in the bucket, around the walls of the bucket and on the surface first.  The air is still -10C so the bucket, the liquid and the ice will keep getting colder.  The ice on the surface will drop to slightly below 0C but very slowly since it is still absorbing the heat of the not-yet-frozen water.  Eventually, the entire bucket of water will be frozen and will be just below 0C.  First the walls of the bucket will reach -10C (same as the air tempertaure).  The ice near the walls of the bucket and on the surface will reach -10C first, continually absorbing the heat energy from the relatively warmer ice near the center of the bucket.  Until finally, the entire bucket of ice is steady at -10C.  That is until the sun comes out or the day gets warmer.\n\n\nAnd by the Way, dry ice is not water, it's frozen CO2 (Carbon Dioxide)\n\nOne more thing, at a near perfect vacuum, you can actually cool liquid water to less than 0C without it freezing.  Never tried that but I did accidently freeze a beer last night...