Last Effective Flower & Frost Analysis
Home » Last Effective Flower & Frost Analysis

Average dates for the Last Effective Flower at key locations for different times when crops are anticipated to be finished (Last Harvestable Boll).

Estimates are based on a cotton boll development rate function, combined with frost risk analysis, leveraging 30 years of historical climate data from the State of Queensland’s SILO patched point dataset.

A key observation, particularly for cooler growing regions, is that as the date of LHB is delayed, the time of LEF is not increasingly delayed.

Date of Last Effective Flower (LEF)

 Desired date for your crop to be finished       (Last Harvestable Boll – LHB)

Frost Analysis
Location
  14th   March
21st March
28th March
07th April
14th April
21st April
28th April
07th May
 Average First Frost Date Earliest  Recorded Frost Date 20th Percentile Frost Date 80th Percentile Frost Date Latest  Recorded Frost Date
Jerilderie LEF Date 15-Jan 20-Jan 24-Jan 29-Jan 1-Feb 4-Feb 7-Feb 10-Feb 17-May 22-Apr 5-May 30-May 20-Jun
Ave. # of Days LEF to LHB 58 61 64 69 72 76 80 86
Griffith LEF Date 17-Jan 22-Jan 26-Jan 31-Jan 31-Jan 11-Feb 10-Feb 13-Feb 16-May 22-Apr 2-May 30-May 20-Jun
Ave. # of Days LEF to LHB 57 59 62 66 74 70 78 84
Hay LEF Date 17-Jan 21-Jan 25-Jan 31-Jan 3-Feb 6-Feb 9-Feb 13-Feb 16-May 13-Apr 1-May 30-May 13-Jul
Ave. # of Days LEF to LHB 57 59 62 67 70 74 78 84
Hillston LEF Date 18-Jan 23-Jan 27-Jan 2-Feb 5-Feb 9-Feb 12-Feb 15-Feb 15-May 22-Apr 4-May 30-May 18-Jun
Ave. # of Days LEF to LHB 55 58 60 65 68 72 76 81
Warren LEF Date 19-Jan 24-Jan 29-Jan 4-Feb 8-Feb 11-Feb 15-Feb 18-Feb 31-May 22-Apr 13-May 14-Jun 18-Jul
Ave. # of Days LEF to LHB 54 56 59 63 66 69 73 78
Narromine LEF Date 17-Jan 22-Jan 27-Jan 1-Feb 5-Feb 9-Feb 12-Feb 15-Feb 17-May 22-Apr 7-May 27-May 18-Jun
Ave. # of Days LEF to LHB 56 58 61 65 69 72 76 81
Bourke LEF Date 23-Jan 28-Jan 2-Feb 8-Feb 12-Feb 16-Feb 19-Feb 23-Feb 1-Jun 30-Apr 15-May 13-Jun 27-Jul
Ave. # of Days LEF to LHB 51 53 55 59 61 65 68 73
Walgett LEF Date 20-Jan 26-Jan 30-Jan 6-Feb 10-Feb 14-Feb 17-Feb 21-Feb 23-May 30-Apr 9-May 31-May 18-Jun
Ave. # of Days LEF to LHB 53 55 57 61 64 67 70 75
Wee Waa LEF Date 19-Jan 24-Jan 29-Jan 5-Feb 9-Feb 13-Feb 16-Feb 20-Feb 23-May 28-Apr 9-May 4-Jun 18-Jun
Ave. # of Days LEF to LHB 55 56 58 62 65 68 71 76
Narrabri LEF Date 18-Jan 23-Jan 28-Jan 4-Feb 8-Feb 12-Feb 15-Feb 19-Feb 19-May 22-Apr 6-May 29-May 24-Jun
Ave. # of Days LEF to LHB 55 57 59 63 66 69 73 77
Gunnedah LEF Date 15-Jan 20-Jan 25-Jan 31-Jan 4-Feb 8-Feb 11-Feb 15-Feb 14-May 12-Apr 4-May 24-May 18-Jun
Ave. # of Days LEF to LHB 58 60 63 66 70 73 77 82
Quirindi LEF Date 13-Jan 18-Jan 22-Jan 28-Jan 1-Feb 4-Feb 8-Feb 11-Feb 7-May 5-Apr 26-Apr 20-May 28-May
Ave. # of Days LEF to LHB 61 63 66 70 73 76 80 85
Burren Junction LEF Date 20-Jan 25-Jan 30-Jan 5-Feb 9-Feb 13-Feb 17-Feb 21-Feb 24-May 30-Apr 10-May 6-Jun 18-Jun
Ave. # of Days LEF to LHB 54 56 58 61 64 67 71 76
Spring Ridge LEF Date 15-Jan 19-Jan 24-Jan 30-Jan 3-Feb 7-Feb 10-Feb 14-Feb 12-May 12-Apr 5-May 23-May 18-Jun
Ave. # of Days LEF to LHB 59 61 63 67 71 74 78 83
Moree LEF Date 19-Jan 24-Jan 29-Jan 5-Feb 9-Feb 13-Feb 17-Feb 21-Feb 26-May 23-Apr 14-May 11-Jun 27-Jun
Ave. # of Days LEF to LHB 55 56 59 62 65 68 71 76
Mungindi LEF Date 21-Jan 26-Jan 1-Feb 7-Feb 11-Feb 15-Feb 19-Feb 24-Feb 5-Jun 1-May 16-May 25-Jun 10-Jul
Ave. # of Days LEF to LHB 53 54 56 59 62 65 68 73
St George LEF Date 21-Jan 26-Jan 1-Feb 7-Feb 12-Feb 16-Feb 20-Feb 24-Feb 3-Jun 1-May 16-May 15-Jun 21-Aug
Ave. # of Days LEF to LHB 53 54 56 59 62 65 68 72
Goondiwindi LEF Date 19-Jan 25-Jan 29-Jan 5-Feb 10-Feb 14-Feb 18-Feb 22-Feb 26-May 28-Apr 14-May 8-Jun 30-Jun
Ave. # of Days LEF to LHB 55 56 58 61 64 67 70 74
Dalby LEF Date 15-Jan 20-Jan 26-Jan 1-Feb 6-Feb 10-Feb 15-Feb 19-Feb 20-May 28-Apr 8-May 29-May 26-Jun
Ave. # of Days LEF to LHB 59 60 62 65 67 70 73 77
Forest Hill LEF Date 11-Jan 17-Jan 22-Jan 29-Jan 3-Feb 8-Feb 12-Feb 17-Feb 14-Jun 9-May 31-May 27-Jun 18-Jul
Ave. # of Days LEF to LHB 62 63 65 68 71 73 75 79
Murgon LEF Date 11-Jan 17-Jan 22-Jan 29-Jan 3-Feb 8-Feb 12-Feb 17-Feb 28-May 1-May 15-May 9-Jun 26-Jun
Ave. # of Days LEF to LHB 62 63 65 68 71 73 75 79
Maryborough LEF Date 14-Jan 19-Jan 25-Jan 1-Feb 7-Feb 12-Feb 16-Feb 22-Feb 14-Jul 10-Jun 29-Jun 1-Aug 26-Aug
Ave. # of Days LEF to LHB 60 61 63 65 67 69 71 75
Theodore LEF Date 18-Jan 24-Jan 29-Jan 6-Feb 11-Feb 16-Feb 20-Feb 26-Feb 7-Jun 10-May 20-May 24-Jun 4-Jul
Ave. # of Days LEF to LHB 55 56 58 60 62 65 67 71
Emerald LEF Date 20-Jan 26-Jan 1-Feb 9-Feb 14-Feb 19-Feb 24-Feb 1-Mar 11-Jul 30-May 20-Jun 9-Aug 20-Aug
Ave. # of Days LEF to LHB 53 54 56 58 59 61 64 67
** 30 year historical record mean data ** 30 year historical record data
 Last Effective Flower date estimated using a development rate function and SILO dataset.
This is the estimated date, that on average, when analysing the climate record, indicates the date of the last effective flower for desired date of crop maturity (LHB).		 Historical record dates of average first frost, earliest recorded, 20th, 80th percentile and latest recorded as analysed via the SILO dataset.

General guide only. Not comprehensive or specific technical advice. Circumstances vary from farm to farm. To the fullest extent permitted by law, CSD expressly disclaims liability for any loss or damage arising from reliance upon any information, statement or opinion on this website or from any errors or omissions on this website.

 

Climate observation data obtained via the State of Queensland SILO patched point dataset.

20th percentile indicates 80% of the time first frost occurred after this date, and 20% of the time prior to this date.

80th percentile indicates 20% of the time first frost occurred after this date, and 80% of the time prior to this date.