First of all, here is a list of units and events availability updated on v2.2.
(+ tp) - means tropical version is available too
(l) - means late war version of the given unit type
+ - means the player get and extra one from the unit for free
WEATHER - I pointed out the fixed starts and ends of the winter weather
* - means the extra units is only given if some circumstances exists (mostly the player is on the loosing path, or have not yet captured given major objectives/cities).
AXIS:
4., + Italian Arm 1., + Brandenburgers, Bf 110F
5., + FW 190A (hero)
6., + Ju.87D (Africa), + Bf 190F-4 (hero, Africa), + PzIIC, + PzIIIE (both released)
7., -
8.,+ MC.202 (hero), Pz IIIJ (+tp), Pz IVF1 (tp), 50mm AT, Do-217E (no more Do-17 reinforcements)
9., RAIN, + Tirpitz, Stu IIIE, BF 110E (tp), Ju 88A (tp), He 111H (tp), Ju 88D (tp)
10., RAIN, MUD, + Sub (Kiel), Battleships 50 fuel max
11., CLOUDS, MUD, Fw 190A-2, Ju.87D, It. Lancia 100/17 (Art. on truck)
12., SNOWFALL, SNOW, SiG 33 (+tp), Bf 110F (tp), , Lates time to bring Hun troops home,-1 WINTER Strenghts at the end of the turn
13., SNOWFALL, + parachute mines, + T-34/M41, -1 WINTER Strenghts, (Allied SU counter-attack!)
14., SNOWFALL, 15cm Arty (+transport), 2x Chetnicks Inf, + ... Inf, Battleships 20/15 fuel max, -1 WINTER Strenghts
15., CLOUDY/SNOWFALL, SNOW, + it. Semovente 75/18
16., CLOUDY/SNOWFALL, SNOW, It. M14/41 (+tp)
17., CLOUDY, SNOW, Pz IIIJ/1 (+tp), Sdkfz 7/2
18., CLEAR, SNOW, + Finnish 122mm Arty
19. RANDOM WEATHER, Nbwf 21cm, +100 prestige/turn, HS 126 - Ends, + FW 189A (recon)
20., + 2x Radar, + 2x Sub, + Axis minor prestige income
21., + Black Sea fleet, + Hungarian army, (Allied: + Soviet train transports)
22., + Romanian army
23., Marder IID, Pz IVF/2, Marder III (+tp), Re.2001 (+tp), It. Lancia da 90/53 (AA on truck), Ju 87D(tp), + armor conversion possibilities
24., + Italian army 2. , Rom IAR-80B
25., Core limit: 225, Sdkfz 222 (late), Pz IVG, StuG IIIF (+tp), It. Cannone 90/53 (AA), It. Fiat CR.42 bomber (tp), Bf 109G-2, Sdkfz 221 (l), + Ju88D (recon), + 4x German Inf, Upgrade possibility 3x Bf 109's to Fw 190's
26., + Roma Battleship, + Fw 190A-5, + 88AA, Pz IIIN (+tp), Rom JRS-79B, Finn T-26/39, Hun 14/31M 149mm Arty, MC.202 (+tp)
27., Marder II, Pz IIIL, 75/38 AT(UE transport), (Allied: Dieppe next turn - only if no major city is captured in England)
28., -
29., It. Semovente 47/32 AT (+tp), Hun 29M 80mm AA, Hun 31M 149mm Art.
30., + 2x Sub(Kiel, France), Rom IAR-81 (tac. bomber), (Allied: sometimes a British Sub approaches at Malta region)
31., -
32., -
33., RSO transport,StuG IIIF/8, 75mm AT (+tp) with truck, sdkfz, RSO transport, + S-Boat (Black Sea), (Allied: Suez counter-attack)
34., + Naval air rec. (Kiel), (Allied: Torch ships)
35., Bf 109G-2 (tp), Hun/Rom 50mm AT, (Allied: + Sov. Sub at Leningrad, Yak-1B)
36., SNOWFALL, DRY, + Parachute mines, Pz IIIM
37., + Tiger, + It. army 3., Rom IAR-81C
38., + StuG IIIG, Sdkfz 233, Marder IIIH (+tp), (Allied: Yak-7b)
39., Pz IVG(late) (+tp), StuG IIIG (+tp), FW 190A-5, (+tp), He 177A, Movable late AA's
40., + 2x Sub (Kiel, France)
41., + Bf110G, Bf 110G, (Allied: T-34/43)
42., + HS 129 (tac. bomber)
43., +100 prestige/turn, + ger destroyer, Pz IIIM (l), Wespe, Bf 109G-6 (+t), It. Semovente 90/53 (AT), StuH 42, Rom/Finn Bf 109G-2), It. 75/39 AT, Hun Turan I (tank),
44., CLEAR, DRY, Axis minor prestige income 2.
45., +3 Radar, + 88AA, Hummel, It. Re 2002 (+tp), It. Semovente 75/34, Panzerwerfer42, Hummel, Marder IIIM (+tp), (Allied: La-5)
46., + Graf Zeppelin (Ger Carrier), Ju.87G
47., + JG 11 (Ger fighter), JG 1 (-75xp), Range-4 Ger Arty, Pz IVH, Rom 75 97/38 AT (horse)
48., Core limit: 250, + Ferdinand (AT), + 3x Ger. Inf, + AA**, + 75/38 AT**, + Ger Mot Inf, T-34/43 automatic upgrade
49., + Me-410, Sdkfz 250/9 (rec), StuG IIIG (late), Panther D, Hun 75/38 AT
50., + Ger S-Boat, + 3x Sub (Kiel, France), Me-410, MC.205
51., + Fw 190F, 88AT, Turan II, Fw 190F (bomber), Fw 190A-6 (+t), Re 2005, Fw 190A-6
52., G.55 Centauro (It. fighter)
53., Semovente 105/25
54., -
55., + destroyer, It. AB 43, cheaper Sdkfz transports
56., Panther A, Sdkfz 250/11 (rec), Elephant upgrade, Tirpitz -9 strength (random from now on)
57., + 17cm Arty (range-5), + Croat Inf, + Wespe*, + 10.5cm Arty (horse)*, +2x Stug IIIG* (*loosing path), 2x AA, + 88AA, It 75/46 AT, StuH 42 (late), Pz II Luchs (rec), Blue Division OFF, Elephant upgrade, It. 75/46 AT, Ger. 75 AT/horse
58., + 1*-2x Go-145 (tac. bomber)
59., + Cossacks, 234/2 Puma (rec)
60., SNOWFALL, DRY
61., + Ju 88G, + 2 parachute mines, Ju 88G, Pz IVH (late) (+t)
62., CLOUDY/SNOWFALL, + Ger Skijäger Inf,
63., + Subs, 12,8cm AA, Stug IV, Ger. 44 Inf's, Hun Toldi IIa, Hun Zrínyi II (assault art.), Hun 15cm Nebelwerfer, Skijäger, Rom 100, 150mm Art, Rom TAs (Stug),
64., +2x Ger. Inf (Latvian, if territory occupied)*, Slovak Inf OFF,
65., + JG 300 (Ger fighter), Rom T-4 (PzIVH), Ju 188A, It Semovente 105/25 (Assault Art)
66., + 10,5cm AA, + 88AA, +3 Mines, + 3 Strongpoints, Mine units, Strongpoint units
67., Fw 190A-8 (+t), Jpz IV/48, Rom 75/40 AT (truck), It. P26/40, JpgPz IV/75, It. Inf'44
68., DRY, Vezuv in Italy erupts
69., + Hun Bf 109G-6 (hero), + Hun Me-210Ca-1 (tac. bomber), + Fw 190G, Rom Bf 109G-6, Finn Bf 109G-6, Hun 75/40 AT (truck), 2nd Allied bomber arriving at Romanian oil fields!
70., + subs, + Huszar Inf (Hun cavalry), + Hummel* (loosing path), + 88AA, + 15cm Arty*, + 10,5cm Arty, +20mm AA, +Jagdpz IV/48, +StuG IIIG, Möbelwagen (AA)
71., Tiger (late), (Allied use SU airfields too)
72., + Fw 190F, Pz IVJ, Hun Pz IVH, (Allied D-day!)
73., + Fall 44 Inf*, + Marder I*, Me 163B*, Fw 190G (+t), Panther G
74., Sdkfz 234/1, + V-1's, 3rd Allied bomber arriving at Romanian oil fields!
75., + Geb Jäger Inf (hero), + Ju 88G, Tiger II
76., + 88AA, + Hetzer (AT), Marder III - Hetzer free upgrade, Bf 109G-14
77., + Bf 109G-8 (rec),Bf 109G-8, + Ger cav inf, + Ger Inf (French Legion), + 100 prestige/turn (if...), 4th, 5th Allied bomber arriving at Romanian oil fields!, Soviet island invasion SW of Tallin* (96:24)
78., + Fw 190G, (Allied: Operation Anvill - South France invasion*)
79., + Tiger II* (loosing path), Finns surrender (if...), Wirbelwind (AA), Turan III, (Allied: Slovak partisan uprising)
80., + Me 163B, + Ju 88G, + Subs, (Allied: Market-Garden!)
81., + Hetzer* (loosing path), + 88AT, + 10,5cm Arty, Jpz IV/70, Fw 190D (fighter)
82., + StuG's, + Jagdpanther* (loosing path)
83., Bf 190G-10, + V-2's, Hun Bf 109G-14, Hun Fw190F
84., -
85., SNOWFALL, DRY, P 30/43,Ostwind (AA)
86., Bf 109K-4, Dangerius beach hexes no more...
87., Ju88G, Volksturm Inf, + Volksturm Inf units (many), Hun Tas tank, Hun Tas tank destroyer
88., -
89., + Jagdtiger* (loosing path)
90., + Me 262
91., DRY
92., Ar 234B, Ta 152H, JG 1 - He 162A, KG 76 - Ar 234B
93., + Ar 233B
94., He 162A, Do 335A, + Sub XXI, Tiger II (late)
95., -
96., -
97., -
98., -
99., Uhu

----------------------------------------
ALLIED (only some important ones):
33., T-70
35., Yak-1B
38., Yak-7B
41., T-34/43
45., La-5 (from Lag-3), Sextron (brit tracked Arty)
55., P-47C
66., + 100 prestige
68., Churchill MK VII
70., P-47D, M-24 Chaffee (rec)
77., M4A1(76)W (USA)
81., Sherman Firefly (Brit)
83., Spitfire XIV