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Relative Flowering Times for Broadleaf Weeds (GDD 50)
through Mon, Mar. 30. 2026

 

GDD Total: 33 (Base 50) through Mon, Mar. 30, 2026

  

Madison, WI

        

Forecast »

“Flashback” to 2025

3/29

3/30

3/31

4/1

4/2

4/3

4/4

4/5

4/6

4/7

4/8

4/9

4/10

Late Season (Biennials and Perennials)

1401

Mid Season and Late Season (SA and Perennials)

601

Mid Season (Perennials)

201

Early and Mid Season (WA and Perennials)

21

Early Season (WA)

5

 

Generously Supported By:



Tabular Data

Daily GDD accumulation for various base temperature models in 2025 & 2026

2026Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
02-15 32° 57° 23 13 3 0 0
02-16 33° 63° 49 29 9 0 0
02-17 34° 52° 70 40 10 0 0
02-18 42° 57° 97 57 17 0 0
02-19 28° 49° 113 63 17 0 0
02-20 27° 36° 123 63 17 0 0
02-21 24° 27° 126 63 17 0 0
02-22 17° 23° 126 63 17 0 0
02-23 16° 28° 127 63 17 0 0
02-24 18° 35° 132 63 17 0 0
02-25 21° 30° 135 63 17 0 0
02-26 13° 42° 141 63 17 0 0
2026Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
02-27 28° 59° 163 75 19 0 0
02-28 19° 41° 171 75 19 0 0
03-01 12° 30° 171 75 19 0 0
03-02 18° 44° 180 75 19 0 0
03-03 30° 44° 195 80 19 0 0
03-04 21° 53° 210 85 19 0 0
03-05 40° 47° 232 97 21 0 0
03-06 41° 59° 260 115 29 0 0
03-07 34° 58° 284 129 33 0 0
03-08 32° 60° 308 143 36 0 0
03-09 46° 71° 344 170 53 9 4
03-10 36° 50° 365 180 54 9 4
2026Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
03-11 31° 38° 377 183 54 9 4
03-12 28° 43° 391 186 54 9 4
03-13 31° 44° 406 192 54 9 4
03-14 25° 35° 414 192 54 9 4
03-15 26° 33° 422 192 54 9 4
03-16 18° 26° 422 192 54 9 4
03-17 4° 21° 422 192 54 9 4
03-18 17° 37° 427 192 54 9 4
03-19 29° 50° 444 200 54 9 4
03-20 36° 64° 473 218 62 9 4
03-21 42° 70° 506 242 76 15 5
03-22 36° 56° 530 255 80 15 5
2026Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
03-23 28° 44° 544 259 80 15 5
03-24 32° 51° 564 269 80 15 5
03-25 38° 73° 597 292 93 20 5
03-26 37° 57° 622 307 98 20 5
03-27 27° 42° 635 310 98 20 5
03-28 20° 47° 646 312 98 20 5
03-29 40° 64° 676 331 108 22 5
03-30 43° 79° 715 360 126 33 11
03-31 42° 72° 750 385 141 40 13
04-01 34° 48° 768 394 141 40 13
04-02 33° 53° 789 404 142 40 13
04-03 37° 51° 811 416 144 40 13
2026Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
04-04 35° 43° 829 424 144 40 13
04-05 31° 52° 848 433 144 40 13
04-06 34° 45° 866 441 144 40 13
04-07 20° 43° 875 441 144 40 13
04-08 32° 64° 901 457 150 40 13
04-09 46° 59° 932 477 160 42 13
04-10 38° 59° 958 494 167 42 13
04-11 43° 63° 989 514 178 45 13
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
02-15 20° 27° 2 0 0 0 0
02-16 7° 25° 2 0 0 0 0
02-17 -7° 6° 2 0 0 0 0
02-18 -10° 8° 2 0 0 0 0
02-19 -2° 10° 2 0 0 0 0
02-20 0° 23° 2 0 0 0 0
02-21 3° 25° 2 0 0 0 0
02-22 12° 27° 2 0 0 0 0
02-23 16° 35° 5 0 0 0 0
02-24 35° 51° 26 11 1 0 0
02-25 31° 49° 45 19 1 0 0
02-26 31° 44° 60 25 1 0 0
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
02-27 32° 44° 76 31 1 0 0
02-28 31° 54° 97 41 2 0 0
03-01 17° 30° 98 41 2 0 0
03-02 12° 35° 99 41 2 0 0
03-03 30° 47° 116 48 2 0 0
03-04 39° 49° 138 60 4 0 0
03-05 27° 42° 150 62 4 0 0
03-06 22° 39° 159 62 4 0 0
03-07 31° 37° 171 64 4 0 0
03-08 22° 48° 184 67 4 0 0
03-09 31° 60° 207 81 7 0 0
03-10 34° 67° 236 99 15 1 0
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
03-11 33° 53° 256 110 16 1 0
03-12 30° 52° 276 119 16 1 0
03-13 29° 64° 300 134 21 1 0
03-14 42° 77° 338 161 38 10 5
03-15 35° 58° 362 176 43 10 5
03-16 28° 40° 374 178 43 10 5
03-17 19° 57° 391 184 43 10 5
03-18 37° 61° 418 202 50 10 5
03-19 33° 41° 433 207 50 10 5
03-20 29° 39° 445 209 50 10 5
03-21 29° 59° 467 221 52 10 5
03-22 28° 45° 482 225 52 10 5
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
03-23 33° 47° 500 233 52 10 5
03-24 30° 46° 516 239 52 10 5
03-25 28° 48° 532 245 52 10 5
03-26 30° 54° 552 255 52 10 5
03-27 42° 59° 580 273 60 11 5
03-28 45° 79° 620 304 81 23 12
03-29 36° 69° 651 324 91 25 12
03-30 33° 39° 664 328 91 25 12
03-31 31° 45° 681 334 91 25 12
04-01 25° 41° 692 335 91 25 12
04-02 35° 66° 720 353 99 26 12
04-03 38° 50° 742 365 101 26 12
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
04-04 31° 50° 760 374 101 26 12
04-05 36° 49° 781 384 102 26 12
04-06 29° 52° 799 393 102 26 12
04-07 29° 43° 813 397 102 26 12
04-08 20° 43° 823 397 102 26 12
04-09 33° 49° 842 405 102 26 12
04-10 33° 43° 858 411 102 26 12
04-11 29° 54° 877 421 102 26 12
04-12 31° 62° 901 435 107 26 12
04-13 48° 62° 934 458 119 30 12
04-14 48° 58° 965 479 130 33 12
04-15 36° 53° 988 492 133 33 12
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
04-16 29° 54° 1007 501 133 33 12
04-17 37° 60° 1034 517 139 33 12
04-18 50° 65° 1069 543 155 41 15
04-19 44° 59° 1098 562 164 42 15
04-20 37° 52° 1121 574 166 42 15
04-21 44° 55° 1148 592 174 42 15
04-22 37° 70° 1180 614 186 46 15
04-23 45° 72° 1216 640 202 54 18
04-24 54° 72° 1257 671 223 67 26
04-25 46° 54° 1285 689 231 67 26
04-26 42° 59° 1313 707 239 67 26
04-27 38° 68° 1344 728 250 70 26
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
04-28 52° 84° 1390 764 276 88 39
04-29 50° 75° 1431 795 297 101 47
04-30 38° 66° 1461 814 306 103 47
05-01 47° 53° 1488 832 314 103 47
05-02 47° 58° 1519 852 324 105 47
05-03 43° 54° 1545 869 331 105 47
05-04 39° 64° 1575 888 340 106 47
05-05 45° 63° 1607 911 353 110 47
05-06 45° 77° 1646 940 372 121 53
05-07 52° 68° 1683 967 389 131 57
05-08 40° 64° 1713 987 399 133 57
05-09 34° 71° 1744 1008 410 135 57
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
05-10 52° 73° 1784 1038 430 148 65
05-11 39° 75° 1820 1063 445 155 67
05-12 45° 83° 1862 1096 468 169 76
05-13 59° 76° 1907 1131 493 187 89
05-14 57° 82° 1955 1169 521 207 103
05-15 58° 87° 2006 1209 551 229 121
05-16 56° 81° 2052 1246 578 248 135
05-17 50° 63° 2086 1270 592 254 136
05-18 47° 64° 2120 1294 606 259 136
05-19 39° 55° 2145 1309 611 259 136
05-20 42° 50° 2169 1323 615 259 136
05-21 45° 50° 2194 1338 620 259 136
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
05-22 44° 59° 2224 1358 630 261 136
05-23 43° 64° 2255 1379 641 265 136
05-24 41° 64° 2286 1400 652 267 136
05-25 44° 68° 2320 1424 666 273 137
05-26 43° 68° 2353 1447 679 278 137
05-27 54° 71° 2394 1477 699 291 145
05-28 54° 61° 2429 1503 715 298 147
05-29 49° 68° 2466 1530 732 307 151
05-30 49° 73° 2505 1559 751 318 157
05-31 48° 70° 2542 1586 768 328 162
06-01 43° 73° 2578 1612 784 336 165
06-02 51° 83° 2624 1648 810 353 177
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
06-03 63° 82° 2674 1688 840 376 195
06-04 58° 73° 2718 1722 864 391 205
06-05 52° 76° 2760 1753 885 405 214
06-06 58° 78° 2805 1789 911 422 226
06-07 56° 76° 2849 1823 935 438 237
06-08 54° 72° 2890 1854 956 452 246
06-09 55° 64° 2928 1882 974 461 250
06-10 53° 73° 2970 1913 995 475 259
06-11 60° 86° 3021 1954 1026 498 277
06-12 61° 77° 3067 1991 1053 517 291
06-13 54° 75° 3110 2024 1076 531 300
06-14 53° 79° 3154 2058 1100 547 311
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
06-15 59° 76° 3199 2093 1125 565 324
06-16 63° 81° 3250 2134 1156 587 341
06-17 66° 84° 3303 2177 1189 612 361
06-18 64° 74° 3350 2214 1216 631 375
06-19 62° 82° 3401 2254 1246 654 393
06-20 67° 85° 3454 2298 1280 680 414
06-21 74° 92° 3516 2349 1321 713 442
06-22 77° 92° 3578 2402 1364 747 471
06-23 68° 92° 3636 2450 1402 777 496
06-24 68° 82° 3689 2493 1435 802 516
06-25 70° 84° 3744 2538 1470 830 539
06-26 70° 90° 3802 2586 1508 859 563
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
06-27 68° 80° 3854 2628 1540 883 582
06-28 62° 83° 3905 2669 1571 906 600
06-29 70° 89° 3962 2716 1608 935 624
06-30 66° 84° 4015 2759 1641 960 644
07-01 63° 82° 4066 2799 1671 983 662
07-02 64° 86° 4118 2842 1704 1008 682
07-03 66° 89° 4174 2887 1739 1035 704
07-04 69° 87° 4230 2933 1775 1063 727
07-05 71° 88° 4288 2981 1813 1093 752
07-06 70° 80° 4341 3024 1846 1118 772
07-07 59° 81° 4389 3062 1874 1138 787
07-08 65° 83° 4440 3104 1906 1162 806
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
07-09 65° 81° 4491 3145 1937 1184 823
07-10 62° 81° 4541 3185 1967 1206 840
07-11 67° 76° 4591 3224 1996 1228 857
07-12 68° 82° 4643 3267 2029 1252 876
07-13 60° 80° 4691 3305 2057 1272 891
07-14 61° 84° 4742 3346 2088 1295 909
07-15 65° 86° 4795 3389 2121 1321 930
07-16 67° 85° 4849 3433 2155 1347 951
07-17 59° 69° 4891 3465 2177 1360 959
07-18 50° 77° 4933 3497 2199 1374 968
07-19 69° 84° 4987 3541 2233 1400 989
07-20 65° 77° 5036 3580 2262 1421 1005
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
07-21 57° 80° 5083 3617 2289 1440 1019
07-22 62° 85° 5134 3658 2320 1463 1037
07-23 71° 89° 5193 3706 2358 1494 1063
07-24 73° 81° 5248 3752 2394 1521 1085
07-25 69° 82° 5301 3795 2427 1546 1105
07-26 68° 83° 5355 3838 2460 1572 1126
07-27 67° 89° 5411 3885 2497 1600 1149
07-28 73° 90° 5470 3934 2536 1631 1175
07-29 71° 85° 5526 3980 2572 1659 1198
07-30 60° 73° 5570 4014 2596 1676 1210
07-31 59° 74° 5615 4049 2621 1692 1221
08-01 52° 75° 5656 4080 2642 1705 1229
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
08-02 50° 77° 5698 4112 2664 1719 1238
08-03 53° 77° 5741 4145 2687 1734 1248
08-04 55° 79° 5786 4180 2712 1751 1260
08-05 58° 81° 5834 4217 2739 1771 1275
08-06 57° 82° 5881 4255 2767 1790 1289
08-07 65° 88° 5936 4300 2802 1817 1311
08-08 70° 88° 5993 4347 2839 1846 1335
08-09 74° 87° 6052 4395 2877 1877 1361
08-10 67° 77° 6101 4435 2907 1898 1377
08-11 69° 82° 6155 4479 2941 1924 1398
08-12 68° 81° 6208 4522 2974 1949 1418
08-13 62° 80° 6257 4561 3003 1970 1434
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
08-14 59° 81° 6305 4599 3031 1991 1450
08-15 66° 86° 6360 4643 3065 2017 1471
08-16 68° 84° 6414 4688 3100 2043 1492
08-17 67° 78° 6464 4728 3130 2065 1509
08-18 66° 77° 6514 4768 3160 2087 1526
08-19 66° 79° 6565 4808 3190 2110 1544
08-20 66° 76° 6614 4847 3219 2131 1560
08-21 59° 76° 6659 4883 3245 2148 1572
08-22 60° 79° 6707 4921 3273 2168 1587
08-23 59° 74° 6751 4955 3297 2185 1599
08-24 54° 69° 6791 4985 3317 2197 1606
08-25 50° 67° 6828 5011 3333 2205 1609
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
08-26 49° 71° 6865 5039 3351 2214 1613
08-27 48° 73° 6904 5067 3369 2225 1619
08-28 58° 74° 6948 5101 3393 2241 1630
08-29 50° 66° 6984 5128 3410 2249 1633
08-30 57° 73° 7027 5161 3433 2264 1643
08-31 49° 74° 7066 5190 3452 2275 1649
09-01 49° 75° 7106 5220 3472 2287 1656
09-02 52° 76° 7148 5252 3494 2301 1665
09-03 52° 67° 7186 5280 3512 2311 1670
09-04 42° 62° 7216 5300 3522 2313 1670
09-05 50° 61° 7250 5324 3536 2319 1671
09-06 44° 63° 7282 5345 3547 2323 1671
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
09-07 42° 65° 7313 5367 3559 2326 1671
09-08 40° 71° 7346 5390 3572 2331 1671
09-09 52° 75° 7388 5422 3594 2345 1680
09-10 54° 74° 7430 5453 3615 2359 1689
09-11 56° 78° 7475 5488 3640 2376 1701
09-12 54° 82° 7521 5524 3666 2394 1714
09-13 64° 80° 7571 5565 3697 2416 1731
09-14 62° 83° 7622 5605 3727 2439 1749
09-15 60° 84° 7671 5645 3757 2461 1765
09-16 57° 85° 7721 5685 3787 2482 1782
09-17 58° 85° 7770 5724 3816 2503 1798
09-18 59° 84° 7820 5763 3845 2525 1815
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
09-19 64° 81° 7870 5804 3876 2548 1832
09-20 64° 76° 7918 5842 3904 2567 1847
09-21 60° 78° 7965 5879 3931 2586 1861
09-22 58° 78° 8011 5915 3957 2605 1874
09-23 60° 74° 8056 5950 3982 2621 1886
09-24 55° 65° 8094 5978 4000 2631 1891
09-25 49° 75° 8134 6008 4020 2643 1898
09-26 54° 84° 8181 6045 4047 2662 1912
09-27 58° 85° 8230 6084 4076 2684 1928
09-28 48° 80° 8272 6116 4098 2698 1937
09-29 53° 87° 8320 6154 4126 2718 1952
09-30 54° 83° 8367 6191 4153 2736 1966
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55

 

Latest Updates

February 16th, 2026Welcome to the 2026 GDD Tracking Season

Although Punxsutawney Phil saw his shadow predicting six more weeks of winter, GDDTracker will start counting on February 15. Spring is when GDDTracker receives the most attention for alerting turfgrass managers of optimal application timing windows for suppressing annual bluegrass seedheads and crabgrass preemergence applications. As spring turns to summer, there are several models that may be helpful throughout the season including the early season dollar spot DMI timer and the Smith-Kerns dollar spot prediction model. To learn about all the available models, click on the "About" tab at the top of the screen. Thanks for your continued support and use of GDDTracker and best wishes for a successful 2026!


 

March 18th, 2024Timing crabgrass preemergence applications in spring

Don't miss this update from from Kevin Frank regarding timing of crabgrass preemergence herbicides.


 

 

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