The first firebombing raid was on Kobe on February 3, 1945, and following its relative success the USAAF continued the tactic. Japanese cities were susceptible to such attack, but the most favorable conditions for success were areas with few firebreaks and high surface winds. Much of the armor and defensive weaponry of the bombers was also removed to allow increased bomb loads, but ultimately loads were increased by the use of low altitudes for fuel conservation, with individual aircraft bomb loads increasing from 2.6 tons per plane in March to 7.3 tons in August.
The first such raid on Tokyo was on the night of February 23–24, when 174 B-29s destroyed around one square mile (~2.56 km²) of the city. Following on that effort 334 B-29s took off from the Mariana Islands on the night of March 9–10 heading for Tokyo. After 2 hours of bombardment, Tokyo was engulfed in a firestorm. The fires were so hot they would ignite the clothing on individuals as they were fleeing. Many women were wearing what were called 'air-raid turbans' around their heads and the heat would ignite those turbans like a wick on a candle. The aftermath of the incendiary bombings lead to an estimated 100,000 Japanese dead. This may have been the most devastating single raid ever carried out by aircraft in any war including the atomic bombings of Hiroshima and Nagasaki. Around 16 square miles (41 km²) of the city were destroyed in the fire storm. The destruction and damage was at its worst in the city sections east of the Imperial Palace. In the following two weeks there were almost 1,600 further sorties against the four cities, destroying 31 square miles (80 km²) in total at a cost of 22 aircraft. There was a third raid on Tokyo on May 26.
The firebomb raids were not the only raids on Tokyo; there were more regular raids using conventional high explosives. With the capture of Okinawa, the Eighth Air Force was transferred there from Europe and began its own raids. Monthly tonnage dropped on Japan had increased from 13,800 short tons in March to 42,700 tons in July (from 12,500 to 38,700 metric tons), and was planned to have continued to increase to around 115,000 short tons (105,000 metric tons) per month.