Air Operations, Bismarcks

V Bomber Command B-17s and B-24s attack airfields in the Rabaul area and Gasmata.

Air Operations, CBI

• 9 341st Medium Bomb Group B-25s attack a railway bridge at Meza.

• 11 11th Medium Bomb Squadron B-25s and 14 23Rd Fighter Group P-40s attack the airfield at Nanchang.

Air Operations, East Indies

V Bomber Command B-25s attack Dili and Koepang, Timor.

Air Operations, Europe

• 60 B-17 bombers of the US 8th Air Force attack the submarine shipyards at Kiel. The Luftwaffe put up their stiffest opposition yet and during the aerial battle that follows at least 22 American aircraft are brought down. Another attack on Bremen by 102 B-17s is only lightly opposed.

Bremen, June 13, 1943

• There is a night raid on Grimsby. Many 'Butterfly' anti-personnel bombs and incendiaries are dropped. 74 people are killed and 130 injured.

• 13 Mosquitos are sent to attack cities in Germany

  6 to Berlin, 4 to Düsseldorf and 3 to Cologne. All the targets are covered in cloud and only estimated postions are bombed. 18 Wellingtons and 12 Stirlings are sent to lay mines off the Biscay ports and there are 8 OTU sorties.

• 1 mine-laying Wellington is lost.

140 VIII Fighter Command short-range P-47s are sent on sweeps over France, Belgium, and the Netherlands. Luftwaffe engage the 56th Fighter Group formation over northern France which results in the downing of 3 FW-190s.

• Although the main daylight bombing attack atainst Bremen by 122 1st Heavy Bomb Wing B-17s is lightly opposed by Luftwaffe fighters, 22 of the 72 4th Heavy Bomb Wing B-17s dispatched on a diversionary strike against Kiel are downed and 24 are damaged. As a result of the mission's high losses, ranking proponents of the daylight bombing strategy are given more than ample justification for reassessing the need for changing strategies to favor long-range fighter escorts.
• 1st Heavy Bomb Wing losses: 4 B-17s lost, 31 damaged; 8 crewmen wounded, 32 missing; 4th Heavy Bomb Wing crew: 3 killed, 20 wounded, 213 missing

Air Operations, Mediterranean

350th Fighter Group P-39 dive-bombers down 2 FW-190s over Pantelleria during the afternoon.

Air Operations, New Guinea

V Bomber Command B-25s attack barges along coastal areas and B-24s mount individual attacks against the Malahang airfield at Lae and a freighter in Humboldt Bay.

Air Operations, Sicily

24 376th Heavy Bomb Group B-24s attack Gerbini Airdrome, and 22 98th Heavy Bomb Group B-24s join RAF bombers for an attack against the Catania Airdrome.

Air Operations, Solomons

XIII Bomber Command B-17s and B-24s attack the Kahili airfield on Bougainville.

Battle of the Atlantic

The US Coast Guard cutter Escanaba (PG-77) is sunk off Ivigtut, Greenland by a German submarine torpedo.

Germany, Strategy

The start date for CITADEL passes. Hitler is still waiting for his Panther tanks.

Mediterranean

The garrison on the small island of Linosa surrenders unconditionally to the Allies.

New Guinea

The Americans and Australians, preparing for the new offensive, reorganize by forming new 'Forces' consisting of a pair of infantry battalions supported by groups of gunners. These formations will be more suitable to the kind of warfare conducted on the island.

Parade in Cairo

Pacific

• The Japanese submarine I-31 is sunk by the US destroyer Frazier (DD-607) in the Aleutian Islands area.
• The US submarine Guardfish (SS-188) sinks the Japanese army cargo ship Suzuya Maru (901t) off the southwest coast of New Ireland.
• The US submarine Sargo (SS-188) attacks a Japanese convoy 250 miles south of Yap, Carolines, and sinks the army transport Konan Maru (5226t). The submarine is damaged by depth charges but remains on patrol.