<P> Temperatures of 90 ° F (32 ° C) and above are quite uncommon (with the exception of dry, leeward areas). In the leeward areas, temperatures may reach into the low 90's several days during the year, but temperatures higher than these are unusual . The highest temperature ever recorded on the islands was 100 ° F (38 ° C) on April 27, 1931 in Pahala . </P> <P> The other reason for the small variation in air temperature is the nearly constant flow of fresh ocean air across the islands . Just as the temperature of the ocean surface varies comparatively little from season to season, so also does the temperature of air that has moved great distances across the ocean; the air brings with it to the land the mild temperature regime characteristic of the surrounding ocean . In the central North Pacific, the trade winds represent the outflow of air from the great region of high pressure, the North Pacific High, typically located well north and east of the Hawaiian Islands . </P> <P> The Pacific High, and with it the trade - wind zone, moves north and south with changing angle of the sun, so that it reaches its northernmost position in the summer . This brings trade winds during the period of May through September, when they are prevalent 80 to 95 percent of the time . From October through April, the heart of the trade winds moves south of Hawaii; however, the winds still blow much of the time . They provide a system of natural year - long ventilation throughout the islands and bring mild temperatures characteristic of air that has moved great distances across tropical waters . </P> <Table> <Tr> <Th_colspan="14"> hide Climate data for Hawaii </Th> </Tr> <Tr> <Th> Month </Th> <Th> Jan </Th> <Th> Feb </Th> <Th> Mar </Th> <Th> Apr </Th> <Th> May </Th> <Th> Jun </Th> <Th> Jul </Th> <Th> Aug </Th> <Th> Sep </Th> <Th> Oct </Th> <Th> Nov </Th> <Th> Dec </Th> <Th> Year </Th> </Tr> <Tr> <Th> Record high ° F (° C) </Th> <Td> 93 (34) </Td> <Td> 94 (34) </Td> <Td> 95 (35) </Td> <Td> 100 (38) </Td> <Td> 98 (37) </Td> <Td> 97 (36) </Td> <Td> 98 (37) </Td> <Td> 98 (37) </Td> <Td> 98 (37) </Td> <Td> 97 (36) </Td> <Td> 96 (36) </Td> <Td> 97 (36) </Td> <Td> 100 (38) </Td> </Tr> <Tr> <Th> Average high ° F (° C) </Th> <Td> 79 (26) </Td> <Td> 79 (26) </Td> <Td> 79 (26) </Td> <Td> 79 (26) </Td> <Td> 81 (27) </Td> <Td> 82 (28) </Td> <Td> 82 (28) </Td> <Td> 84 (29) </Td> <Td> 84 (29) </Td> <Td> 84 (29) </Td> <Td> 81 (27) </Td> <Td> 79 (26) </Td> <Td> 81 (27) </Td> </Tr> <Tr> <Th> Average low ° F (° C) </Th> <Td> 68 (20) </Td> <Td> 68 (20) </Td> <Td> 70 (21) </Td> <Td> 70 (21) </Td> <Td> 72 (22) </Td> <Td> 73 (23) </Td> <Td> 75 (24) </Td> <Td> 75 (24) </Td> <Td> 75 (24) </Td> <Td> 75 (24) </Td> <Td> 73 (23) </Td> <Td> 70 (21) </Td> <Td> 72 (22) </Td> </Tr> <Tr> <Th> Record low ° F (° C) </Th> <Td> 14 (− 10) </Td> <Td> 12 (− 11) </Td> <Td> 18 (− 8) </Td> <Td> 18 (− 8) </Td> <Td> 12 (− 11) </Td> <Td> 23 (− 5) </Td> <Td> 22 (− 6) </Td> <Td> 17 (− 8) </Td> <Td> 23 (− 5) </Td> <Td> 20 (− 7) </Td> <Td> 20 (− 7) </Td> <Td> 17 (− 8) </Td> <Td> 12 (− 11) </Td> </Tr> <Tr> <Th> Average precipitation inches (mm) </Th> <Td> 3.07 (78) </Td> <Td> 3.54 (89.9) </Td> <Td> 3.46 (87.9) </Td> <Td> 2.05 (52.1) </Td> <Td> 1.50 (38.1) </Td> <Td> 1.69 (42.9) </Td> <Td> 2.24 (56.9) </Td> <Td> 1.34 (34) </Td> <Td> 2.40 (61) </Td> <Td> 3.15 (80) </Td> <Td> 4.88 (124) </Td> <Td> 3.43 (87.1) </Td> <Td> 32.75 (831.9) </Td> </Tr> <Tr> <Th> Average precipitation days </Th> <Td> 18 </Td> <Td> 16 </Td> <Td> 19 </Td> <Td> 19 </Td> <Td> 18 </Td> <Td> 20 </Td> <Td> 22 </Td> <Td> 19 </Td> <Td> 17 </Td> <Td> 18 </Td> <Td> 20 </Td> <Td> 19 </Td> <Td> 225 </Td> </Tr> <Tr> <Td_colspan="14"> Source #1: </Td> </Tr> <Tr> <Td_colspan="14"> Source #2: </Td> </Tr> </Table>

When do the trade winds blow in hawaii