Japanese attack the Aleutian Islands (part of Alaska, USA) with a bombing raid on US naval base at Dutch Harbor, Unalaska Island, 200 miles West of the Alaskan Peninsula. They have 3 aims; first, to distract the Americans from the main event at Midway; secondly, to draw out any American warships defending the Aleutians to destroy them using carrier aircraft; and thirdly, to occupy 2 small islands further West in the island chain to forestall any possible US attack on Japan across the Northern Pacific (although these landings will be delayed in the event of a naval battle). At 2.43 AM in dense fog, 12 dive bombers and 6 Zero fighters take off from light aircraft carrier Junyo (they shoot down a US flying boat but then get lost and return to Junyo) and 11 torpedo bombers plus 6 Zeros take off from light carrier Ryujo, reaching Dutch Harbor. They find no ships in the harbor for their torpedoes but instead strafe the Army barracks and radio station as well as taking reconnaissance photographs (25 US troops killed, 2 Japanese bombers shot down by anti-aircraft fire). A fuel leak forces a Zero fighter to crashland in the tundra on a small island, killing the pilot. The Zero will be recovered intact 5 weeks later and transported back to USA for analysis, revealing defensive weaknesses in armor, lack of self-sealing fuel tanks and other safety flaws.
At 4.10 AM 400 miles Northeast of San Juan, Puerto Rico, U-172 torpedoes American SS City of Alma which sinks immediately on her cargo of 7400 tons of manganese ore (29 killed, 10 survivors picked up 4 days later by American patrol boat USS YP-67). At 9.26 AM, U-156 sinks British schooner Lillian (running passengers and rum between Caribbean islands) with 322 rounds of gunfire (3 dead, 22 survivors). From 5 AM to 10 AM 245 miles Northwest of Bermuda, U-404 attacks and sinks neutral Swedish SS Anna (all 17 hands rescued).
In the morning, US Catalina PBY seaplanes from Midway spot elements of the Japanese fleet, providing crucial information on location, direction and speed. At 12.30 PM, 9 US B-17 bombers take off from Midway and bomb Japanese troop transport ships 660 miles West of Midway 3 hours later but score no hits n the face of heavy anti-aircraft fire from the escorts.
Luftwaffe aircraft continue bombarding Sevastopol along with German artillery, including two 600mm (24 inch) siege mortars Thor and Odin. From June 2 to 6, Thor and Odin fire 19 heavy concrete-piercing shells weighing 2,170 kg and carrying 289 kg of explosive which make a crater 15m wide and 5m deep.
In the Atlantic 400 miles East of Guyana, U-126 attacks Norwegian tanker MV Høegh Giant all day, finally sinking her at 1.40 AM next morning (all 39 hands survive but have a long and harrowing return to safety).
At dusk 35 miles East of Sydney, Australia, Japanese submarine I-24 is recharging her batteries on the surface when lookouts spot Australian coastal freighter SS Age in the distance. I-24 fires a torpedo and 4 rounds from the deck gun but cannot chase SS Age which escapes undamaged. 90 minutes later, I-24 sinks Australian SS Iron Chieftain Iron Chieftain with a torpedo (12 killed).
At 9 PM 40 miles off the Western end of Nova Scotia, U-432 sinks 2 tiny unarmed US fishing boats with shellfire, after allowing the crews to escape. At 9.56 PM 150 miles Northwest of Trinidad, U-502 sinks US tanker SS MF Elliott (13 killed; 27 survivors picked up at dawn next day by US destroyer USS Tarbell; 2 survivors are questioned on board U-502 for 3 hours, put on a raft with provisions and picked up 5 days later by Brazilian tanker SS Santa Maria).
Overnight, RAF 170 aircraft bombers attack Bremen, Germany, causing damage to housing, the harbour and German destroyer Z-25 (83 dead, 258 injured, 4 Wellingtons, 2 Halifaxes, 2 Lancasters, 2 Stirlings, 1 Manchester lost). Luftwaffe bombers attack Poole, England.