Rainfall of 20.8 mm in June 2020 was far below the average (44 mm), reaching only to the 28th percentile.
Although this low rainfall did not cause any rainfall total for 12-months or less to become a serious shortage, all totals for longer durations were serious shortages or worse. Two were serious (<10th %-ile), six were severe (<5th %-ile), and nine were extreme (<1st %-ile). Nearly all of them had become drier than in May.
The 42-month total, which had set a driest record of 1468 mm in April, now beat this with 1457 mm in June. At two other durations, rainfall totals were 2nd-driest: at 84-months, 3471 mm; and at 96-months, 4142 mm.
How to read the graph
This graph shows all the present rainfall shortages at Manilla, short term and long term, as percentile values. The latest values are shown by a thick black line with large circles. Those from one month earlier are shown by a thinner line with small diamonds. [The method is described in “Further Explanation” below.]
The following notes explain aspects of this work under these listed headings:
Cumulative rainfall totals
Severity of rainfall shortages
Limitations of this analysis
Monthly rainfalls form a single population
Observations are not retrospective
The rain gauge failed