September 1: The Luftwaffe begins operation Wasserkante as part of the invasion of Poland. The first air attacks against Warsaw start.
September 2: Single PZL.23B of the 21st Squadron of Polish Air Force bombs a factory in Ohlau. The attack represented the first Allied bombing raid to be conducted against a target in territory within the Third Reich.
September 3: The RAF launches its first raid of the war over Germany territory. Eighteen Handley Page Hampdens and nine Vickers Wellingtons are sent to attack the German warships moored at the Wilhelmshaven naval base. However poor visibility prevents the bombers from finding any targets before nightfall so they return.
September 27: The Luftwaffe ceases its bombing campaign against Warsaw after its Polish garrison surrenders to German forces. Approximately 1,150 sorties were flown by a wide variety of aircraft, including obsolete Junkers Ju 52/3m bombers.
November 30: The Winter War between Soviet Union and Finland starts. Three hours after Soviet forces had crossed the border and started the Winter War, Helsinki is bombed. Throughout the war, the Soviet Union has the air superiority and several cities in Finland are targeted.
December 18: The first use of radar for defence (an "experimental Freya radar") gave warning of RAF bombers near the German Bight as they made an attack on Wilhelmshaven.:20 However the German fighters were not permitted to intercept until visual confirmation was made - the bombers were attacked after they had dropped their bombs.
September 7: The Blitz bombing of Britain began with 57 nights of air raids
September 8: Three Dornier 17 bombers are downed by a single shot from a "Territorial gun crew" near Farnington.:129
9 September: A bombing raid on Tel Aviv caused 137 deaths.
19 October: Four SM.82 bombers attacked American-operated oil refineries in the British Protectorate of Bahrain, damaging the local refineries. The raid also struck Dhahran in Saudi Arabia, but causing little damage.
September 15: In a single day, the Luftwaffe loses 60 aircraft over England during the Battle of Britain:68
November 30: The second phase of The Blitz began against British industrial and port cities
January 21: As revenge for the British raids on Berlin, Germany started the Baby Blitz (planned since 27 November).:396
April 8/9: The largest force to date (272 aircraft) bomb Hamburg
April 17: The Augsburg Raid is the first to attempt low-level daylight bombing for accuracy - in this case against the factory producing engines for U-boats. Half of the 12 bombers were shot down for little damage caused.
May 30: The first use of the bomber stream and the first British large scale operation, as part of Operation Millennium the first "Thousand Bomber" raid is sent against Cologne, Germany. Of the 1,047 aircraft sent, nearly 900 bombed the target area - the whole raid passing over in 90 minutes.
June 11–12: First American daylight raid over European soil, against petroleum wells, in Ploiești Romania amongst objectives in Bulgaria the first stages of American Bombing offensive 
July 4: The first American bombing mission over enemy-occupied territory in Europe used 20 Boston bombers (plus 6 RAF-crewed Bostons) to attack the Alkmaar, Hammsted, and Valkenburg airfields -- :106 only two reached the target area (two shot down, the others heavily damaged):111
August 14: First German warplane downed by the USAAF. A German Fw 200 Condor reconnaissance-bomber is shot down by two US fighter pilots, flying a P-40 Warhawk and a P-38 Lightning, off the coast of Reykjavík, Iceland. All six German airmen are killed as the plane explodes and goes into the sea.
August 15: 82nd Airborne is the first US airborne division. (the first combat jumps were 8 November 1942 by the 509th Parachute Battalion in the North Africa Operation Torch).:106,107
August 17: 12 B-17s of the 97 BG (including one with Eaker aboard) escorted by RAF Spitfires bombed the Sotteville railyard 3 miles (4.8 km) South of Rouen, France, in the "first combat action" of the Eighth Air Force and the first B-17 bombing of Europe.
August 19: 22 B-17's drop 34 tons of bombs on Abbeville/Drucat A/F in France causing extensive damage.
August 20: 11 of 12 B-17's bomb Amiens/Longeau Marshilling Yard, France at 1801 hours without loss.
August 21: 12 B-17's are dispatched to bomb the shipards in Rotterdam, Netherlands but is aborted due to an attack by Bf 109s and Fw 190s; 1 bomber is damaged; Lack of proper coordination with the Spitfire escorts is a major factor in the failure of the mission.
August 24: 12 B-17s bomb the shipyard of Ateliers et chantier
August 1: Flying from North Africa Operation Tidal Wave bombs the oil refineries at Ploiești. A large number of the bombers are lost for little strategic benefit. Five Medals of Honor are awarded to American aircrew.
November 1: A Combined Bomber Offensive progress report estimates that 19/19/9 German towns & cities have been virtually destroyed/severely damaged/more effectively damaged – another report claims 10% of German war potential had been destroyed
November 3: A Wilhelmshaven raid is the first Eighth Air Force blind-bombing mission to completely destroy the aiming point, the Eighth's first 500-plane mission, and the first use by the US of H2X radar
November 22/23: The largest force sent to bomb Berlin to date (764 aircraft) conducted the most effective World War II raid on Berlin
December 2: 100 Ju-88s bombed the port of Bari, hitting a secret store of US mustard gas (83 of the sailors died within a month). Autopsies indicated excess white blood cells, and the discovery led to the use of the gas to combat leukemia (the secret regarding the storage at Bari of mustard gas was subsequently declassified in 1959).:149
January 30: The first U.S. Intruder operation was conducted by P-47s and accurately preceded the bombers to strike fighters at Villaorba airfield.
February 6–27: During the Continuation War, between Soviet Union and Finland several Finnish cities were bombed. The greatest air raids once again targeted Helsinki. In this manner the USSR hoped to force Finland to break its ties with Germany and agree to a peace settlement.
February 19/20: Handley Page Halifax IIs and Vs were permanently withdrawn from operations to Germany after 14.9% of those that did not turn back were lost on a raid to Leipzig.
June 2–5: In preparation for Operation Overlord, Operation Cover bombed transportation and airfield targets in Northern France and "coastal defenses, mainly located in the Pas de Calais coastal area, to deceive the enemy as to the sector to be invaded".
June 8: The first use of the Azon guided bomb targeted the Melun bridge
July 28: The first operational use of rocket-powered point-defense interceptors occurs as Me 163Bs of I. Gruppe/JG 400 take off from Brandis to defend against a USAAF strategic bombing raid on the Merseburg/Leuna synthetic fuel production complex.
August 27: The RAF restarted daylight bombing of Germany (first since 12 August 1941) with an attack on the Homberg Fischer-Tropsch plant in Hamburg.:149
January 5: The first mission of Operation Cornflakes begins when a mail train to Linz was bombed. Fake mailbags containing anti-Nazi propaganda were then dropped on the wreckage in the hope the letters would be unwittingly delivered by the Reichspost. The OSS dropped two million Das Neue Deutschland (German: The New Germany) propaganda newspapers during this psychological warfare operation; which ended in February.:104
February 13–15: The Allied Bombing of Dresden causes a firestorm that kills up to 25,000 people in the city.
March 12: The RAF drop 4,851 tonnes of bombs on Dortmund using 1108 aircraft (748 Lancasters, 292 Halifaxes, 68 Mosquitos). Up to 98% of buildings in the city center are destroyed. It would be the heaviest raid on a single target in World War II.
March 18: The largest number of Me 262s to date launch their most concentrated attacks against Allied bomber formation. Mission 894 attacking Berlin (1,329 bombers and 733 fighters) loses 13 bombers and 6 fighters. The AAF claim 25 Luftwaffe aircraft.
April 19: The last RAF air operation using Grand Slam bombs in Europe takes place over Heligoland. Twenty aircraft from 617 Squadron, six with Grand Slams and the remainder with smaller Tallboy bombs, along with 16 aircraft from 9 Squadron attack the island's coastal gun-batteries. No aircraft were lost. A total of 42 Grand Slams were dropped in air operations over Germany.
^ abIrving, David (1964). The Mare's Nest. London: William Kimber and Co. p. 223. ISBN0-586-06368-4. NOTE: V-2 rocket air operations were conducted by various German Army units, but operational orders were issued by a Joint Services (OKW) command.
^ abcdefGalland, Adolf (1968 Ninth Printing – paperbound) . The First and the Last: The Rise and Fall of the German Fighter Forces, 1938–1945. (translated by Mervyn Savill). New York: Ballantine Books. ISBN0-553-11709-2. Check date values in: |year= (help)
^Jablonski, Edward (1971). Volume 1 (Tragic Victories), Book II (The Big League). Airpower. p. 71.
Forrester, Larry (1973) . Fly for Your Life: The Story of R. R. Stanford Tuck, D.S.O, D.F.C. and Two Bars. Sir Max Aitken (Foreword). Garden City, New York: Nelson Doubleday. ISBN0-553-11642-8.
^Smith, J. Richard & Eddie J. Creek (1997). Blitz!: Germany's Arado Ar 234 Jet Bomber. Merriam Press. p. 23. ISBN9781576380079.
^Flower, Stephen (2004). Barnes Wallis’ Bombs. Researched from the original records and interviews with those involved with the development and use of the bombs. Stroud: Tempus. pp. 362–64. ISBN0-7524-2987-6.
^Till, Major Noel O (September 1945). Report on Investigations, WO 309/1592. No. 2 War Crimes Investigation Team. From the Till report of June 1945: "The Intelligence Officer with 83 Group RAF has admitted on two occasions; first to Lt H. F. Ansell of this Team (when it was confirmed by a Wing Commander present), and on a second occasion to the Investigating Officer when he was accompanied by Lt. H. F. Ansell, that a message was received on 2 May 1945 that these ships were loaded with KZ prisoners but that, although there was ample time to warn the pilots of the planes who attacked these ships on the following day, by some oversight the message was never passed on... From the facts and from the statement volunteered by the RAF Intelligence Officer, it appears that the primary responsibility for this great loss of life must fall on the British RAF personnel who failed to pass to the pilots the message they received concerning the presence of KZ prisoners on board these ships." See: Jacobs and Pool, 2004 and Till, 1945