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Early Season Fungicide App for Dollar Spot Suppression (GDD 50)
forecast for Sun, May. 31. 2026

 
  

Zionsville, IN

        

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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 39° 54° 25 15 5 0 0
02-16 34° 58° 48 28 8 0 0
02-17 37° 56° 73 43 13 0 0
02-18 47° 68° 109 69 29 8 3
02-19 47° 64° 142 92 42 14 4
02-20 31° 54° 163 103 43 14 4
02-21 25° 34° 170 103 43 14 4
02-22 19° 28° 172 103 43 14 4
02-23 16° 27° 172 103 43 14 4
02-24 15° 39° 177 103 43 14 4
02-25 33° 50° 197 113 43 14 4
02-26 31° 47° 214 120 43 14 4
2026Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
02-27 34° 62° 240 136 49 14 4
02-28 34° 58° 264 150 53 14 4
03-01 29° 37° 275 151 53 14 4
03-02 25° 39° 285 151 53 14 4
03-03 35° 43° 302 158 53 14 4
03-04 41° 54° 328 174 59 14 4
03-05 53° 62° 363 199 74 21 6
03-06 58° 76° 408 234 99 38 18
03-07 43° 66° 441 257 111 42 18
03-08 37° 58° 466 272 117 42 18
03-09 43° 70° 500 296 131 49 19
03-10 63° 70° 545 331 156 65 31
2026Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
03-11 36° 70° 576 352 167 68 31
03-12 30° 47° 593 359 167 68 31
03-13 41° 55° 619 375 173 68 31
03-14 33° 47° 637 383 173 68 31
03-15 41° 72° 671 407 187 75 32
03-16 21° 55° 687 413 187 75 32
03-17 15° 23° 687 413 187 75 32
03-18 22° 48° 700 416 187 75 32
03-19 37° 69° 731 437 199 78 32
03-20 49° 77° 772 468 220 91 40
03-21 43° 72° 807 493 235 98 43
03-22 47° 83° 850 526 258 113 52
2026Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
03-23 32° 44° 866 532 258 113 52
03-24 27° 53° 884 540 258 113 52
03-25 40° 69° 917 563 270 117 52
03-26 56° 82° 964 600 297 137 67
03-27 36° 52° 986 612 299 137 67
03-28 29° 48° 1002 618 299 137 67
03-29 37° 64° 1031 637 308 137 67
03-30 54° 75° 1074 670 331 152 76
03-31 63° 76° 1121 707 358 172 91
04-01 41° 70° 1155 731 372 177 92
04-02 40° 78° 1192 758 389 186 96
04-03 65° 77° 1241 797 418 208 112
2026Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
04-04 45° 70° 1277 823 434 216 115
04-05 41° 52° 1301 837 438 216 115
04-06 39° 56° 1327 853 444 216 115
04-07 33° 48° 1345 861 444 216 115
04-08 35° 67° 1374 880 453 217 115
04-09 54° 76° 1417 913 476 232 125
04-10 49° 66° 1453 939 491 239 127
04-11 37° 64° 1481 957 500 240 127
04-12 52° 79° 1525 991 523 255 138
04-13 65° 81° 1576 1032 554 278 156
04-14 70° 82° 1630 1076 588 304 177
04-15 66° 78° 1680 1116 618 326 194
2026Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
04-16 63° 75° 1727 1153 645 345 208
04-17 52° 82° 1772 1188 670 362 219
04-18 45° 73° 1809 1215 687 371 224
04-19 35° 56° 1832 1228 690 371 224
04-20 32° 56° 1854 1240 692 371 224
04-21 43° 76° 1891 1267 709 380 228
04-22 61° 78° 1939 1305 737 400 243
04-23 56° 81° 1986 1342 764 419 256
04-24 59° 75° 2031 1377 789 436 268
04-25 54° 72° 2071 1407 810 448 276
04-26 49° 68° 2108 1434 826 457 280
04-27 54° 68° 2147 1463 845 468 285
2026Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
04-28 54° 62° 2183 1489 861 476 289
04-29 49° 61° 2216 1512 874 481 289
04-30 38° 59° 2242 1528 881 481 289
05-01 44° 52° 2269 1545 887 481 289
05-02 37° 53° 2291 1557 890 481 289
05-03 38° 60° 2318 1574 897 481 289
05-04 49° 74° 2358 1604 916 493 295
05-05 45° 67° 2392 1628 930 499 296
05-06 44° 56° 2420 1646 938 499 296
05-07 37° 60° 2446 1662 945 499 296
05-08 47° 64° 2480 1686 959 505 297
05-09 51° 72° 2520 1716 978 516 304
2026Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
05-10 54° 67° 2558 1744 996 526 309
05-11 44° 70° 2593 1769 1011 533 311
05-12 42° 78° 2631 1797 1029 543 316
05-13 50° 68° 2667 1823 1046 552 319
05-14 40° 66° 2698 1844 1057 555 319
05-15 46° 68° 2733 1869 1072 562 321
05-16 59° 75° 2778 1904 1097 579 333
05-17 62° 83° 2829 1945 1127 601 351
05-18 67° 83° 2882 1988 1160 626 371
05-19 66° 84° 2935 2031 1193 651 391
05-20 59° 70° 2978 2064 1216 666 400
05-21 53° 67° 3016 2092 1234 676 405
2026Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
05-22 56° 67° 3055 2121 1253 687 412
05-23 56° 69° 3095 2151 1273 699 419
05-24 58° 72° 3138 2184 1296 714 429
05-25 50° 79° 3181 2217 1319 729 439
05-26 57° 76° 3226 2252 1344 746 450
05-27 67° 75° 3275 2291 1373 767 466
05-28 61° 80° 3323 2329 1401 787 482
05-29 57° 79° 3369 2365 1427 805 495
05-30 57° 79° 3415 2401 1453 823 508
05-31 52° 76° 3457 2433 1475 837 517
06-01 57° 79° 3503 2469 1501 855 530
06-02 57° 79° 3549 2505 1527 873 543
2026Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
06-03 56° 80° 3595 2541 1553 891 555
06-04 59° 83° 3643 2579 1582 912 571
06-05 64° 85° 3696 2622 1614 936 591
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
02-15 32° 40° 14 4 0 0 0
02-16 19° 34° 19 4 0 0 0
02-17 6° 17° 19 4 0 0 0
02-18 5° 15° 19 4 0 0 0
02-19 12° 18° 19 4 0 0 0
02-20 3° 19° 19 4 0 0 0
02-21 12° 27° 19 4 0 0 0
02-22 11° 32° 19 4 0 0 0
02-23 21° 44° 30 5 0 0 0
02-24 33° 52° 50 16 0 0 0
02-25 37° 58° 76 31 6 0 0
02-26 32° 58° 99 45 9 0 0
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
02-27 38° 53° 123 58 13 0 0
02-28 31° 63° 148 73 18 0 0
03-01 21° 44° 158 74 18 0 0
03-02 15° 35° 161 74 18 0 0
03-03 26° 47° 176 78 18 0 0
03-04 43° 65° 208 100 30 4 0
03-05 32° 55° 229 112 32 4 0
03-06 30° 40° 243 115 32 4 0
03-07 31° 44° 258 121 32 4 0
03-08 31° 49° 276 129 32 4 0
03-09 33° 58° 300 142 35 4 0
03-10 35° 66° 329 161 44 5 0
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
03-11 48° 70° 366 188 61 14 4
03-12 38° 72° 398 211 73 19 4
03-13 39° 74° 433 235 88 25 6
03-14 50° 77° 474 267 110 39 14
03-15 56° 69° 515 298 131 52 22
03-16 33° 56° 538 310 133 52 22
03-17 28° 50° 555 317 133 52 22
03-18 42° 74° 591 343 149 60 25
03-19 53° 65° 628 371 167 69 30
03-20 33° 49° 647 380 167 69 30
03-21 28° 55° 667 389 167 69 30
03-22 38° 52° 690 403 170 69 30
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
03-23 34° 45° 707 410 170 69 30
03-24 36° 52° 729 422 172 69 30
03-25 37° 49° 751 433 173 69 30
03-26 30° 53° 770 443 173 69 30
03-27 38° 58° 796 459 179 69 30
03-28 49° 79° 839 491 202 84 39
03-29 61° 70° 882 525 225 99 49
03-30 56° 71° 924 556 247 113 58
03-31 35° 57° 948 570 250 113 58
04-01 29° 52° 966 579 250 113 58
04-02 45° 80° 1007 609 271 125 66
04-03 51° 65° 1042 635 287 133 68
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
04-04 44° 55° 1070 653 295 133 68
04-05 44° 59° 1100 672 304 134 68
04-06 37° 44° 1118 681 304 134 68
04-07 31° 54° 1139 691 304 134 68
04-08 26° 42° 1151 693 304 134 68
04-09 31° 45° 1166 699 304 134 68
04-10 37° 58° 1192 714 310 134 68
04-11 38° 51° 1214 726 312 134 68
04-12 31° 58° 1236 739 314 134 68
04-13 45° 63° 1268 761 326 138 68
04-14 54° 72° 1309 792 347 152 77
04-15 45° 54° 1337 809 355 152 77
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
04-16 37° 58° 1362 824 360 152 77
04-17 40° 66° 1393 845 371 155 77
04-18 56° 78° 1438 880 396 172 89
04-19 53° 72° 1479 911 417 185 97
04-20 49° 73° 1518 941 436 196 103
04-21 53° 69° 1557 970 455 207 109
04-22 47° 72° 1594 997 473 216 113
04-23 51° 77° 1636 1029 495 230 122
04-24 53° 81° 1681 1064 520 247 134
04-25 55° 71° 1722 1095 540 260 142
04-26 44° 59° 1752 1114 550 262 142
04-27 42° 66° 1784 1136 562 266 142
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
04-28 54° 82° 1830 1172 588 284 155
04-29 60° 78° 1877 1209 615 303 169
04-30 49° 70° 1914 1237 632 312 174
05-01 64° 74° 1961 1274 659 331 188
05-02 58° 71° 2004 1306 682 346 197
05-03 53° 61° 2039 1331 697 353 199
05-04 46° 52° 2066 1348 704 353 199
05-05 51° 61° 2099 1372 717 358 200
05-06 50° 71° 2138 1400 736 369 206
05-07 52° 76° 2180 1433 758 383 215
05-08 55° 71° 2221 1463 779 396 223
05-09 42° 68° 2254 1486 792 401 223
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
05-10 43° 78° 2292 1515 810 411 228
05-11 50° 80° 2335 1548 833 426 238
05-12 58° 75° 2380 1582 858 443 250
05-13 61° 73° 2425 1617 883 460 262
05-14 62° 77° 2472 1655 910 479 276
05-15 64° 87° 2526 1698 944 505 297
05-16 63° 84° 2577 1740 975 528 315
05-17 59° 70° 2620 1772 998 543 325
05-18 53° 74° 2661 1804 1019 556 333
05-19 51° 75° 2702 1835 1040 569 341
05-20 53° 67° 2740 1863 1058 579 346
05-21 53° 61° 2775 1888 1074 587 348
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
05-22 49° 57° 2806 1909 1084 589 348
05-23 41° 66° 2838 1931 1096 593 348
05-24 47° 69° 2874 1957 1112 601 351
05-25 51° 62° 2909 1981 1127 608 353
05-26 47° 71° 2946 2009 1144 617 357
05-27 58° 69° 2988 2040 1166 631 366
05-28 58° 67° 3028 2071 1186 643 373
05-29 54° 70° 3068 2101 1206 655 380
05-30 58° 75° 3113 2135 1231 672 392
05-31 56° 73° 3155 2168 1253 686 401
06-01 42° 74° 3191 2194 1269 694 404
06-02 48° 80° 3234 2226 1292 709 414
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
06-03 61° 85° 3285 2267 1323 732 432
06-04 70° 84° 3339 2312 1358 759 454
06-05 67° 74° 3388 2351 1386 779 469
06-06 67° 78° 3438 2391 1417 802 487
06-07 61° 77° 3485 2428 1443 820 500
06-08 63° 78° 3534 2466 1472 841 516
06-09 61° 76° 3580 2502 1498 859 529
06-10 55° 75° 3623 2536 1521 874 539
06-11 57° 84° 3672 2574 1550 895 555
06-12 62° 84° 3723 2615 1581 918 573
06-13 70° 78° 3775 2658 1613 942 592
06-14 67° 75° 3824 2697 1642 963 608
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
06-15 65° 79° 3874 2737 1672 985 625
06-16 66° 81° 3925 2778 1703 1008 643
06-17 69° 83° 3980 2822 1738 1035 665
06-18 69° 85° 4035 2867 1773 1062 687
06-19 68° 81° 4087 2910 1805 1086 706
06-20 64° 83° 4139 2951 1837 1110 725
06-21 70° 91° 4197 3000 1876 1141 751
06-22 75° 92° 4259 3052 1917 1174 779
06-23 74° 93° 4321 3103 1959 1208 808
06-24 75° 92° 4382 3155 2001 1242 837
06-25 75° 90° 4443 3205 2041 1274 864
06-26 73° 91° 4503 3255 2081 1306 891
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
06-27 76° 89° 4563 3305 2121 1338 918
06-28 73° 87° 4621 3354 2159 1368 943
06-29 71° 84° 4677 3399 2195 1396 966
06-30 72° 86° 4734 3447 2232 1425 990
07-01 72° 84° 4790 3493 2268 1453 1013
07-02 63° 85° 4842 3535 2300 1477 1032
07-03 68° 88° 4899 3581 2337 1506 1056
07-04 67° 89° 4954 3627 2372 1533 1078
07-05 70° 91° 5013 3675 2411 1564 1104
07-06 72° 90° 5071 3724 2449 1594 1129
07-07 69° 79° 5123 3766 2482 1619 1149
07-08 62° 86° 5176 3808 2514 1643 1168
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
07-09 71° 83° 5230 3853 2548 1669 1189
07-10 68° 88° 5286 3898 2584 1697 1212
07-11 71° 90° 5345 3947 2623 1728 1238
07-12 74° 85° 5402 3994 2660 1757 1262
07-13 70° 86° 5458 4040 2696 1785 1285
07-14 69° 85° 5512 4085 2730 1811 1306
07-15 71° 85° 5568 4131 2766 1839 1329
07-16 71° 86° 5625 4177 2803 1868 1353
07-17 70° 85° 5680 4223 2838 1895 1375
07-18 67° 82° 5733 4265 2871 1920 1395
07-19 68° 82° 5786 4308 2904 1945 1415
07-20 72° 82° 5841 4354 2939 1972 1437
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
07-21 72° 82° 5896 4398 2974 1999 1459
07-22 65° 84° 5949 4441 3007 2024 1479
07-23 65° 89° 6003 4486 3041 2050 1500
07-24 74° 92° 6064 4537 3082 2083 1528
07-25 76° 88° 6124 4587 3122 2115 1555
07-26 74° 88° 6184 4636 3162 2147 1582
07-27 75° 89° 6244 4687 3202 2179 1609
07-28 74° 87° 6303 4735 3241 2210 1635
07-29 74° 92° 6363 4786 3281 2242 1662
07-30 70° 90° 6422 4834 3320 2273 1688
07-31 66° 76° 6470 4873 3348 2293 1703
08-01 59° 75° 6515 4908 3374 2311 1716
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
08-02 58° 75° 6560 4942 3398 2327 1727
08-03 56° 79° 6605 4978 3423 2344 1739
08-04 62° 80° 6655 5017 3453 2366 1756
08-05 66° 81° 6706 5058 3484 2389 1774
08-06 64° 84° 6758 5101 3516 2413 1793
08-07 66° 87° 6813 5146 3551 2440 1815
08-08 67° 88° 6869 5191 3587 2468 1838
08-09 69° 89° 6926 5238 3624 2497 1862
08-10 68° 90° 6983 5285 3661 2526 1886
08-11 70° 89° 7040 5333 3698 2555 1910
08-12 70° 85° 7096 5378 3734 2583 1933
08-13 68° 85° 7150 5422 3768 2609 1954
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
08-14 65° 86° 7203 5466 3801 2634 1974
08-15 66° 90° 7259 5512 3837 2662 1997
08-16 70° 89° 7317 5560 3875 2692 2022
08-17 70° 88° 7374 5607 3912 2721 2046
08-18 71° 85° 7430 5652 3948 2749 2069
08-19 72° 86° 7487 5699 3985 2778 2093
08-20 69° 75° 7537 5739 4015 2800 2110
08-21 66° 75° 7585 5778 4043 2820 2125
08-22 61° 77° 7632 5815 4071 2840 2140
08-23 61° 78° 7680 5853 4099 2860 2155
08-24 60° 74° 7725 5888 4124 2877 2167
08-25 52° 70° 7765 5917 4143 2888 2173
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
08-26 49° 72° 7803 5946 4161 2898 2178
08-27 48° 76° 7843 5976 4181 2910 2185
08-28 56° 76° 7887 6010 4205 2926 2196
08-29 54° 75° 7930 6042 4228 2941 2206
08-30 50° 75° 7970 6073 4249 2954 2214
08-31 49° 77° 8012 6104 4270 2967 2222
09-01 50° 81° 8055 6138 4293 2982 2232
09-02 54° 83° 8102 6174 4320 3001 2246
09-03 54° 80° 8147 6210 4345 3018 2258
09-04 53° 69° 8186 6239 4364 3029 2264
09-05 52° 73° 8227 6269 4385 3042 2272
09-06 52° 68° 8265 6297 4403 3052 2277
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
09-07 50° 70° 8303 6325 4421 3062 2282
09-08 43° 73° 8339 6351 4437 3070 2285
09-09 47° 77° 8379 6381 4457 3082 2292
09-10 55° 83° 8426 6418 4484 3101 2306
09-11 56° 83° 8473 6456 4511 3120 2320
09-12 55° 86° 8522 6495 4540 3141 2336
09-13 57° 78° 8568 6530 4566 3159 2349
09-14 63° 87° 8621 6573 4599 3184 2369
09-15 59° 88° 8672 6615 4630 3207 2387
09-16 60° 85° 8723 6655 4661 3230 2405
09-17 57° 87° 8773 6695 4691 3252 2422
09-18 59° 88° 8824 6737 4722 3275 2440
2025Lo
(F)		Hi
(F)		GDD
22		GDD
32		GDD
42		GDD
50		GDD
55
09-19 60° 88° 8876 6779 4754 3299 2459
09-20 62° 88° 8929 6822 4787 3324 2479
09-21 65° 81° 8980 6863 4818 3347 2497
09-22 64° 71° 9026 6898 4844 3365 2510
09-23 63° 77° 9074 6936 4872 3385 2525
09-24 64° 78° 9123 6976 4901 3406 2541
09-25 62° 76° 9170 7013 4928 3425 2555
09-26 53° 80° 9215 7047 4953 3442 2567
09-27 53° 85° 9262 7084 4980 3461 2581
09-28 57° 88° 9312 7125 5010 3483 2598
09-29 58° 88° 9363 7166 5041 3506 2616
09-30 59° 84° 9413 7205 5071 3528 2633
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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