<P> Eureka has a cool - summer Mediterranean climate (Köppen Csb). Due to the influence of the Pacific Ocean, its temperatures resemble those of an oceanic climate . Winters are mild and rainy, and summers cool and dry . The average August high temperature of 64.3 ° F (17.9 ° C) is very cool for an area at such a southerly latitude . The seasonal temperature variation is very small; the difference between the August average of 58.5 ° F (14.7 ° C) and the December average of 47.8 ° F (8.8 ° C) is only 10.7 ° F (5.9 ° C), about equal to the temperature difference between day and night . The all - time highest and lowest temperatures recorded in Eureka are 87 ° F (30.6 ° C) on October 26, 1993, and September 2, 2017, and 20 ° F (− 6.7 ° C) on January 14, 1888, respectively . Additionally, Eureka remains the only city on the West Coast of the continental United States to have never recorded a temperature of 90 degrees Fahrenheit . Temperatures occasionally drop to freezing or below . NOAA's weather station averages indicate only 0.18 inches (4.6 mm) of rainfall in July, which is well within the Mediterranean range, only with cooler air than a typical Mediterranean climate . </P> <P> The area experiences coastal fog throughout the year, especially during summer when inland temperatures are significantly warmer . This phenomenon and cool breezes from the Pacific Ocean keep the city relatively cool while areas a few miles inland may have much higher temperatures, with frequent differences in summer and early fall of 30 to 40 ° F (17 to 22 ° C). </P> <P> Annual precipitation averages 40.3 inches or 1,024 millimetres . Measurable precipitation falls on an average of 119 days each year . The wettest "rain year" was from July 1889 to June 1890 with 73.30 inches (1,861.8 mm) and the driest from July 1976 to June 1977 with 17.56 inches (446.0 mm). The greatest monthly precipitation was 23.21 inches (589.5 mm) in December 2002 . The greatest 24 - hour precipitation was 6.79 inches (172.5 mm) on December 27, 2002 . However, historic "100" year dramatic weather events such as the Christmas Week flood of 1955 and, especially, the Christmas flood of 1964, which severely damaged the region, may not be reflected in records listed herein . Snowfall on the coast happens occasionally, averaging only 0.2 inches or 0.0051 metres as of the 1981--2010 normals, but only five years during that period received measurable snowfall . </P> <Table> <Tr> <Th_colspan="14"> (hide) Climate data for Eureka, California (1981--2010 normals, extremes 1886--present) </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> 78 (26) </Td> <Td> 85 (29) </Td> <Td> 78 (26) </Td> <Td> 80 (27) </Td> <Td> 84 (29) </Td> <Td> 85 (29) </Td> <Td> 77 (25) </Td> <Td> 82 (28) </Td> <Td> 87 (31) </Td> <Td> 87 (31) </Td> <Td> 81 (27) </Td> <Td> 77 (25) </Td> <Td> 87 (31) </Td> </Tr> <Tr> <Th> Average high ° F (° C) </Th> <Td> 55.6 (13.1) </Td> <Td> 56.1 (13.4) </Td> <Td> 56.7 (13.7) </Td> <Td> 57.7 (14.3) </Td> <Td> 60.1 (15.6) </Td> <Td> 62.2 (16.8) </Td> <Td> 63.4 (17.4) </Td> <Td> 64.3 (17.9) </Td> <Td> 63.7 (17.6) </Td> <Td> 61.7 (16.5) </Td> <Td> 58.0 (14.4) </Td> <Td> 55.0 (12.8) </Td> <Td> 59.6 (15.3) </Td> </Tr> <Tr> <Th> Daily mean ° F (° C) </Th> <Td> 48.3 (9.1) </Td> <Td> 48.9 (9.4) </Td> <Td> 49.7 (9.8) </Td> <Td> 50.9 (10.5) </Td> <Td> 53.8 (12.1) </Td> <Td> 56.1 (13.4) </Td> <Td> 57.7 (14.3) </Td> <Td> 58.5 (14.7) </Td> <Td> 57.0 (13.9) </Td> <Td> 54.4 (12.4) </Td> <Td> 50.8 (10.4) </Td> <Td> 47.8 (8.8) </Td> <Td> 52.9 (11.6) </Td> </Tr> <Tr> <Th> Average low ° F (° C) </Th> <Td> 41.1 (5.1) </Td> <Td> 41.7 (5.4) </Td> <Td> 42.6 (5.9) </Td> <Td> 44.1 (6.7) </Td> <Td> 47.5 (8.6) </Td> <Td> 50.1 (10.1) </Td> <Td> 52.0 (11.1) </Td> <Td> 52.8 (11.6) </Td> <Td> 50.4 (10.2) </Td> <Td> 47.1 (8.4) </Td> <Td> 43.5 (6.4) </Td> <Td> 40.6 (4.8) </Td> <Td> 46.1 (7.8) </Td> </Tr> <Tr> <Th> Record low ° F (° C) </Th> <Td> 20 (− 7) </Td> <Td> 24 (− 4) </Td> <Td> 29 (− 2) </Td> <Td> 31 (− 1) </Td> <Td> 35 (2) </Td> <Td> 40 (4) </Td> <Td> 43 (6) </Td> <Td> 44 (7) </Td> <Td> 36 (2) </Td> <Td> 32 (0) </Td> <Td> 27 (− 3) </Td> <Td> 21 (− 6) </Td> <Td> 20 (− 7) </Td> </Tr> <Tr> <Th> Average precipitation inches (mm) </Th> <Td> 6.50 (165.1) </Td> <Td> 5.63 (143) </Td> <Td> 5.30 (134.6) </Td> <Td> 3.32 (84.3) </Td> <Td> 1.78 (45.2) </Td> <Td> 0.75 (19) </Td> <Td> 0.18 (4.6) </Td> <Td> 0.31 (7.9) </Td> <Td> 0.59 (15) </Td> <Td> 2.24 (56.9) </Td> <Td> 5.61 (142.5) </Td> <Td> 8.12 (206.2) </Td> <Td> 40.33 (1,024.4) </Td> </Tr> <Tr> <Th> Average snowfall inches (cm) </Th> <Td> 0 (0) </Td> <Td> 0.2 (0.5) </Td> <Td> 0 (0) </Td> <Td> 0 (0) </Td> <Td> 0 (0) </Td> <Td> 0 (0) </Td> <Td> 0 (0) </Td> <Td> 0 (0) </Td> <Td> 0 (0) </Td> <Td> 0 (0) </Td> <Td> 0 (0) </Td> <Td> 0 (0) </Td> <Td> 0.2 (0.5) </Td> </Tr> <Tr> <Th> Average precipitation days (≥ 0.01 in) </Th> <Td> 16.6 </Td> <Td> 14.9 </Td> <Td> 16.2 </Td> <Td> 13.4 </Td> <Td> 9.1 </Td> <Td> 5.8 </Td> <Td> 2.7 </Td> <Td> 3.2 </Td> <Td> 4.4 </Td> <Td> 8.5 </Td> <Td> 15.2 </Td> <Td> 17.5 </Td> <Td> 127.5 </Td> </Tr> <Tr> <Th> Mean monthly sunshine hours </Th> <Td> 140.1 </Td> <Td> 143.7 </Td> <Td> 207.4 </Td> <Td> 253.1 </Td> <Td> 280.5 </Td> <Td> 277.7 </Td> <Td> 273.4 </Td> <Td> 236.5 </Td> <Td> 220.3 </Td> <Td> 175.8 </Td> <Td> 131.3 </Td> <Td> 126.2 </Td> <Td> 2,466 </Td> </Tr> <Tr> <Th> Percent possible sunshine </Th> <Td> 47 </Td> <Td> 48 </Td> <Td> 56 </Td> <Td> 63 </Td> <Td> 63 </Td> <Td> 62 </Td> <Td> 60 </Td> <Td> 55 </Td> <Td> 59 </Td> <Td> 51 </Td> <Td> 44 </Td> <Td> 44 </Td> <Td> 55 </Td> </Tr> <Tr> <Td_colspan="14"> Source: NOAA (sun and relative humidity 1961--1990) </Td> </Tr> </Table>

How many days a year does it rain in eureka ca