Japan extends across 3,000 kilometers of latitude from Hokkaido at 45°N to Okinawa at 24°N, spanning four distinct climate zones. Hokkaido experiences a humid continental climate. Honshu, Shikoku, and Kyushu fall within a humid subtropical zone with regional variations. The Pacific Ocean coastline receives different precipitation patterns than the Sea of Japan coastline due to seasonal monsoons. Okinawa and the Ryukyu Islands possess a subtropical climate with minimal temperature variation year-round. Elevation creates additional microclimates, particularly in the Japanese Alps where peaks exceed 3,000 meters.
The Japan Meteorological Agency divides the country into ten forecast regions. The Pacific side receives most precipitation during June and September from the summer monsoon and typhoons. The Sea of Japan side receives heavy snowfall from November through March when cold Siberian air crosses warm ocean water, creating the lake effect equivalent. Central mountain ranges block these weather systems, creating the sharp contrast between winter conditions on opposite coasts separated by 200 kilometers.
**JANUARY**
Hokkaido records average temperatures of minus 4°C in Sapporo, with daytime highs reaching minus 1°C and nighttime lows dropping to minus 7°C. Snowfall in Sapporo averages 172 centimeters for the month. Daisetsuzan National Park receives over 500 centimeters of cumulative snow by January's end. Shiretoko National Park on the northeast coast experiences drift ice from late January as pack ice from the Sea of Okhotsk reaches the shoreline. The Sapporo Snow Festival construction begins mid-month for the February event.
Tokyo averages 6°C in January with daytime temperatures reaching 10°C and nights dropping to 2°C. Rainfall totals approximately 50 millimeters across seven days. Humidity averages 52 percent. Clear days outnumber cloudy ones, with the Kanto Plain receiving consistent sunshine. Mount Fuji remains closed to climbers, with summit temperatures reaching minus 30°C and sustained winds exceeding 30 meters per second.
Kyoto's January average sits at 4°C, with highs of 9°C and lows near freezing. The city receives approximately 50 millimeters of rain across nine days. Snow falls on average four days per month but rarely accumulates above 5 centimeters in the city center. Arashiyama Bamboo Grove experiences morning frost. The Golden Pavilion occasionally receives photogenic snow cover, though this occurs in only one year out of three based on Japan Meteorological Agency records from 1991-2020.
Kanazawa on the Sea of Japan coast receives 270 millimeters of precipitation in January, primarily as snow. Average snowfall depth reaches 60 centimeters in the city. Takayama in the Japanese Alps records 180 centimeters of cumulative snowfall by month's end. Shirakawa-go's historic villages receive similar amounts, with traditional gassho-zukuri roofs designed to shed heavy snow loads. Roads to Kamikochi valley remain closed, with snow depth exceeding 3 meters.
Osaka averages 6°C with 46 millimeters of rain. Nara sees identical patterns. Hiroshima on the Inland Sea coast averages 5°C with 40 millimeters across seven rain days. Miyajima Island's Itsukushima Shrine experiences occasional frost but rarely snow. The Inland Sea's moderating effect keeps temperatures 2-3 degrees warmer than interior locations at the same latitude.
Fukuoka in northern Kyushu averages 7°C with 68 millimeters of rain across ten days. Nagasaki records 7°C with 73 millimeters. Kumamoto slightly inland averages 6°C. Snow falls occasionally but melts within hours at sea level. Mount Aso's crater area receives 40 centimeters of snow, with access roads requiring chains.
Okinawa Island averages 17°C in Naha, with daytime highs reaching 20°C and nighttime lows of 15°C. Rainfall totals 107 millimeters across ten days. The ocean temperature averages 21°C. This represents Okinawa's coolest month, though outdoor activities remain viable. The Kerama Islands 30 kilometers west experience identical conditions.
**FEBRUARY**
Sapporo's February average remains at minus 3°C, with 129 centimeters of snowfall. The Sapporo Snow Festival runs during the first week, attracting two million visitors who view ice sculptures reaching 15 meters in height. Akan-Mashu National Park hosts ice fishing on frozen Lake Akan, where ice thickness reaches 50 centimeters. Drift ice reaches maximum extent along Shiretoko Peninsula, with tour vessels departing from Abashiri.
Tokyo's temperature rises slightly to 7°C average, with 56 millimeters of rain across six days. Plum blossoms begin blooming in Kyoto's Kitano Tenmangu Shrine during the final week, typically around February 25 based on 30-year averages. The Japan Meteorological Agency tracks plum blossom fronts as precursors to cherry blossom predictions.
Kyoto averages 5°C with similar rainfall to January. Fushimi Inari-taisha hosts Setsubun festivals on February 3 or 4, marking the traditional calendar's spring beginning. Actual spring conditions remain six weeks distant. The Golden Pavilion sees approximately three snow days. Kiyomizu-dera's wooden terrace experiences frost most mornings.
Kanazawa receives 186 millimeters of precipitation, showing the first decline from winter peaks. Snow depth in the city averages 45 centimeters. Takayama maintains 150 centimeters of cumulative snow. The Tateyama Kurobe Alpine Route remains closed, with snow walls not beginning construction until April. Measuring stations on the route record 7 meters of accumulation by February's end.
Osaka and Kyoto begin hosting early plum blossom viewing during the month's final days. Osaka Castle Park's 1,270 plum trees show initial blooms on south-facing slopes. Temperatures average 6°C. Nara's Todai-ji Temple area records identical conditions.
Hiroshima averages 6°C with 64 millimeters of rain. Miyajima Island's maple trees remain bare, with leaf-out not occurring until mid-April. Ferry service to the island operates normally, unaffected by winter weather. The Inland Sea remains calm, with significant waves occurring on fewer than two days per month.
Fukuoka's average rises to 8°C with 70 millimeters of rain. Nagasaki records 8°C with 84 millimeters. Kumamoto sees 7°C. Aso-Kuju National Park maintains 30 centimeters of snow at crater elevations. Access roads reopen during late February in low-snow years.
Naha averages 17°C, identical to January, with 120 millimeters of rain across nine days. Ocean temperature holds at 21°C. Cherry blossoms on Okinawa Island typically bloom in late January or early February, six weeks before Kyushu. The Ryukyu Islands' subtropical climate creates this reverse progression compared to the main islands.
**MARCH**
Sapporo averages 1°C with 109 centimeters of snowfall, showing clear warming trend. By month's end, daytime temperatures reach 5°C, causing afternoon melting. Shiretoko's drift ice begins retreating. Daisetsuzan National Park remains closed to hikers above 1,500 meters due to avalanche risk and snow depth exceeding 4 meters.
Tokyo's March average reaches 10°C with 118 millimeters of rain across twelve days. This represents the wettest March precipitation but not the highest rain-day count. Cherry blossoms typically bloom between March 24-28 based on Japan Meteorological Agency records from 1991-2020. The earliest recorded Tokyo bloom occurred March 16, 2021. Latest was April 5, 1984. Sensoji Temple in Asakusa and Ueno Park host major viewing locations.
Kyoto averages 9°C with 104 millimeters of rain. Cherry blossoms bloom March 28 on average, three days after Tokyo. The Philosopher's Path canal and Maruyama Park represent primary viewing sites. Kiyomizu-dera's 1,500 cherry trees typically reach full bloom during the first week of April. Arashiyama's riverside cherries follow identical timing.
Kanazawa receives 136 millimeters of precipitation, with snow comprising less than half. By month's end, city snow has melted. Kenrokuen Garden's cherry trees bloom around April 5. Takayama receives rain instead of snow during the final ten days. The village maintains 60 centimeters of settled snow at month's end.
Osaka's cherry blossoms bloom March 28 on average. Osaka Castle Park's 3,000 cherry trees reach peak bloom April 3-5. Temperature averages 10°C with 104 millimeters of rain. Nara experiences identical bloom timing, with Nara Park's deer visible beneath flowering branches.
Hiroshima averages 10°C with 95 millimeters of rain. Cherry blossoms bloom March 27, among Japan's earliest on Honshu. Miyajima Island's cherries bloom March 30. The Peace Memorial Park hosts major viewing. Inland Sea ferry routes operate on full schedules as tourism increases.
Fukuoka averages 12°C with 116 millimeters of rain. Cherry blossoms bloom March 23, four days before Hiroshima. Maizuru Park's 1,000 cherry trees peak March 28-30. Nagasaki records similar bloom dates. Kumamoto Castle's 800 cherries follow identical timing despite 2016 earthquake damage to castle structures.
Naha averages 19°C with 161 millimeters of rain across eleven days. This marks Okinawa's wettest month. Ocean temperature rises to 22°C. Cherry blossom season concluded in January. Beaches remain usable but ocean swimming attracts only cold-water enthusiasts.
**APRIL**
Sapporo averages 7°C with 62 millimeters of rain. Snow becomes rare, with the final measurable snowfall typically occurring April 10-15. Cherry blossoms bloom May 3 on average, making Sapporo Japan's last major city to experience bloom. Daisetsuzan National Park trails below 1,000 meters become accessible during the final week.
Tokyo averages 15°C with 125 millimeters of rain across twelve days. Cherry blossoms fall by April 10 in normal years. The Japan Meteorological Agency defines full bloom as 80 percent of blossoms open, lasting approximately seven days before petal fall. Late blooming varieties in Shinjuku Gyoen National Garden extend viewing through April 20. Wisteria blooms begin at Ashikaga Flower Park north of Tokyo around April 20.
Kyoto's April average reaches 14°C with 108 millimeters of rain. Cherry blossoms fall by April 8. Late-blooming yaezakura double-petal varieties at Ninnaji Temple extend viewing through April 15. Wisteria at Byodoin Temple in Uji blooms April 25-May 5. Kyoto National Museum's garden azaleas bloom mid-month.
Kanazawa averages 13°C with 137 millimeters of rain. The Tateyama Kurobe Alpine Route opens April 15, with snow walls reaching 14-18 meters at Murodo, the route's highest point at 2,450 meters. Wall height varies annually based on winter accumulation. The 1991-2020 average maximum wall height is 16 meters, occurring at Otani section. Takayama's spring festival occurs April 14-15, featuring ornate floats first constructed in the 17th century.
Osaka averages 15°C with 103 millimeters of rain. Cherry blossoms conclude by April 10. Wisteria blooms at Shitenno-ji Temple begin April 22. Nara's azaleas at Kasuga Taisha bloom mid-month. Mount Yoshino south of Nara hosts 30,000 cherry trees across four elevation zones, with upper zones blooming through April 20.
Hiroshima averages 15°C with 141 millimeters of rain, representing the month's wettest conditions. Miyajima Island's azaleas bloom late April. The Inland Sea's 3,000 islands show spring green-up. Ferry tourism increases substantially.
Fukuoka averages 16°C with 116 millimeters of rain. Wisteria at Kawachi Fuji Garden reaches peak bloom April 25-May 5, with tunnels covering 1,000 square meters. Nagasaki averages 16°C. Kumamoto records 16°C with azaleas blooming at Suizenji Garden.
Naha averages 22°C with 166 millimeters of rain across eleven days. Ocean temperature reaches 23°C. Swimming becomes comfortable for most visitors. The rainy season locally called tsuyu begins in Okinawa during May, approximately one month before affecting Honshu.
**MAY**
Sapporo averages 12°C with 54 millimeters of rain, representing the city's driest month. Cherry blossoms reach peak bloom May 5-7. Maruyama Park and Moerenuma Park host viewing. Daisetsuzan National Park hiking trails to 1,800 meters become accessible, though snowfields remain above this elevation. Shiretoko National Park's Goko Lakes trail opens May 10 with electric fence protection from brown bears emerging from hibernation.
Tokyo averages 19°C with 138 millimeters of rain across eleven days. Wisteria viewing continues through May 10. Azaleas bloom throughout the month. Shibazakura moss phlox at the base of Mount Fuji near Fujikawaguchiko reaches peak bloom May 1-10, covering 52,000 square meters. Humidity increases noticeably, averaging 65 percent compared to April's 60 percent.
Kyoto averages 19°C with 144 millimeters of rain. Kifune Shrine north of the city offers riverbed dining starting May 1, suspended platforms above the Kibune River operating through September. Kinkaku-ji's gardens show full spring foliage. Arashiyama's cormorant fishing season begins May 15, continuing through September, though this represents tourism entertainment rather than commercial fishing.
Kanazawa receives 153 millimeters of rain, the month's highest precipitation. The Tateyama Kurobe Alpine Route's snow walls decrease to 12-14 meters from April's peak. Kamikochi valley's hiking season begins April 27 when the access road opens. The Kappa Bridge area at 1,500 meters altitude averages 10°C in May.
Osaka averages 20°C with 145 millimeters of rain. Wisteria viewing concludes by May 10. Humidity rises to 64 percent. Nara's Mount Wakakusa becomes accessible after prescribed burning in January creates ash-fertilized grass slopes. The mountain remains closed December through March.
Hiroshima averages 19°C with 181 millimeters of rain, making this the wettest month. Miyajima Island's Daisho-in Temple hosts spring foliage at peak. Itsukushima Shrine's torii gate sits in water during high tide periods, exposing its base during six hours of low tide daily based on lunar cycle.
Fukuoka averages 20°C with 142 millimeters of rain. Nagasaki records 20°C with 193 millimeters, the city's second-wettest month. Kumamoto averages 20°C. Mount Aso's crater area becomes fully accessible with hiking trails open and ropeway operating. Volcanic activity restrictions occasionally close crater rim access, with current status available from Japan Meteorological Agency.
Naha averages 25°C with 231 millimeters of rain across thirteen days. The rainy season tsuyu begins mid-May, defined by sustained frontal rainfall rather than daily downpours. Ocean temperature reaches 25°C. Beach season begins despite rain frequency. Iriomote Island 400 kilometers southwest maintains 90 percent forest cover and receives 250 millimeters in May.
**JUNE**
Sapporo averages 17°C with 64 millimeters of rain across nine days. The city avoids the rainy season affecting regions south of Hokkaido. Clear days remain common. Daisetsuzan National Park trails to 2,200 meters become accessible. Alpine flowers bloom at elevation. Brown bears remain active, with 30-50 sightings reported monthly to park authorities.