Austria: In January, door locks and latches being removed for metal.
Germany: On January 2.3 million exempted workers, half Field Army eligible.
Turkey: 40,594 non-military 1918 deaths in capital (22,244 in 1914).
Britain: RFP 106%, up 10% during 1917. Sugar rationing (1/2 lb per person per week) plus compulsory meatless day (two from January 25). Local lard rationing of 2 oz per person per week for 1.5 million people.
France: In January, Seine freezes over for the first time in 120 years.
Eastern France: Germans exact 92 million Francs from Lille (until October 17).
Flanders: BEF strength 1,907,906 (1,192,668 on January 3, 1917). British 4th Tank Brigade formed. German raids near Loos and Mericourt fail.
Verdun: French repulse raid at Beaumont, and Chaume Wood flamethrower attack (January 12 and 13), make successful raid to southeast on January 16. Gallwitz in command of Army Group for duration of war.
Piave: British cross-river raid succeeds (now 109,103 British troops in Italy).
Salonika: British receive 8-inch gun battery and 12 6-inch Newton mortars and 2 sound-ranging sections.
Macedonia: In January Russian division withdrawn from front and disarmed due to Soviet disaffection, some join French Foreign Legion, at least 14,979 (on April 15) join Allies as labour force but 10,000 Serbs from Russian-Rumanian front corps arrive (via Archangel, Cherbourg, Orange and Taranto). Greek Army has 36,242 troops (3 divisions) and 14,717 animals at front (January 15) plus 18,260 troops in interior (on March 15, 1918).
Britain: Depth charge production up to 4,647 per month, escorts armed with 30-40 each, use 1,745 per month from June.
Germany: Now 21 German MTBs in service, 14 in Flanders.
Channel: Vice-Admiral Keyes takes over Dover Patrol from Admiral Bacon.
Biscay: Acting on Room 40 intercepts, armed boarding steamer HMS Duke of Clarence captures Spanish ship Erro Berro (sinks in tow) before she transfers wolfram (ore-producing tungsten) to 2 U-boats which are ambushed unsuccessfully.
Mediterranean: 2 U-boat Flotillas formed, 1st at Pola, 2nd at Cattaro, 7-8 boats on operations in January, including coastal submarines UB-49 and UB-48 together.
Baltic: Estimated 40,000 sailors have left Russian Fleet for home or interior land fighting.
Germany: During January, Fokker wins first competition to find obsolescent Albatros fighter replacement.
Western Front: In January RFC No 19 Squadron first to receive Sopwith Dolphin high-altitude fighter, No 141 Squadron at Rochford, Essex gets and crashes one but used only as day fighter.
Italy: Austrians bomb Bassano (and on January 4), Treviso (and on January 26) and Mestre (and on January 4 and 26), and Castelfranco on January 4.
Britain: Total air defences have 376 aircraft, 469 anti-aircraft guns, 622 searchlights, 258 height-finders and 10 sound locators.