Ennadai
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Ennadai clear sky chart from 2005-11-06 to 2024-02-05.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.

Observation Type	Minimum conditions for hour to be usable				Out of hours
	Clear of Clouds	Transparency	Seeing	Sky Brightness
Planetary:	50%	(no limit)	Average	(no limit)	Nighttime Hours
Deep Sky:	70%	Average	(no limit)	5.9	Nighttime Hours
CCD Imaging:	70%	Below Average	Poor	(no limit)	Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

By Month

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

		Occurrence of each Forecast	Data Points
Cloud Cover	Day	12% 12% 5% 10% 8% 5% 7% 7% 7% 7% 21%	76631
	Night	9% 12% 6% 11% 10% 6% 8% 8% 8% 8% 14%	82153
Transparency	Day	59% 7% 11% 17% 5%	76284
	Night	63% 6% 11% 15% 6%	82082
Seeing	Day	16% 5% 19% 29% 22% 9%	14905
	Night	14% 4 22% 33% 22% 5%	23086

By Month

Percentage Cloud Cover NW (2006-)
Color Meanings: Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	4 11% 5% 9% 11% 11% 12% 9% 9% 10% 8%	1391
	11th to 20th	Day	4 10% 7% 11% 11% 9% 14% 13% 11% 6% 3	1724
	21st to end	Day	5% 15% 6% 9% 7% 4 7% 8% 12% 15% 13%	2090
February	1st to 10th	Day	3 6% 3 10% 9% 8% 11% 13% 14% 14% 10%	1285
	11th to 20th	Day	4 8% 4 9% 7% 4 8% 10% 13% 17% 15%	1400
	21st to end	Day	1 7% 4 10% 11% 7% 13% 13% 15% 9% 9%	1260
March	1st to 10th	Day	3 7% 5% 11% 9% 6% 9% 11% 10% 12% 18%	1800
	11th to 20th	Day	6% 11% 5% 10% 7% 5% 8% 11% 10% 7% 21%	1870
	21st to end	Day	4 8% 4 11% 11% 7% 8% 11% 8% 8% 21%	2324
April	1st to 10th	Day	6% 12% 6% 11% 9% 5% 7% 10% 9% 7% 18%	2266
	11th to 20th	Day	6% 11% 6% 12% 10% 5% 9% 7% 6% 5% 23%	2394
	21st to end	Day	8% 10% 6% 10% 12% 7% 8% 6% 5% 6% 21%	2632
May	1st to 10th	Day	9% 15% 7% 14% 11% 5% 5% 3 5% 6% 20%	2728
	11th to 20th	Day	9% 12% 7% 14% 9% 5% 5% 4 5% 6% 23%	2903
	21st to end	Day	14% 14% 7% 12% 7% 4 4 4 5% 6% 23%	3305
June	1st to 10th	Day	20% 13% 5% 7% 5% 3 4 5% 5% 6% 26%	3164
	11th to 20th	Day	13% 10% 4 7% 7% 3 5% 6% 6% 7% 31%	3240
	21st to end	Day	11% 7% 2 7% 6% 4 6% 6% 6% 8% 37%	3240
July	1st to 10th	Day	15% 8% 4 7% 7% 4 6% 5% 7% 8% 28%	3240
	11th to 20th	Day	13% 7% 2 6% 6% 4 5% 6% 7% 9% 34%	3092
	21st to end	Day	12% 6% 3 6% 7% 4 6% 6% 7% 8% 36%	3167
August	1st to 10th	Day	18% 7% 3 7% 6% 4 5% 5% 5% 8% 32%	2812
	11th to 20th	Day	17% 10% 4 8% 8% 4 6% 5% 5% 8% 26%	2568
	21st to end	Day	21% 10% 3 7% 6% 4 5% 5% 6% 7% 26%	2709
September	1st to 10th	Day	20% 16% 5% 8% 6% 4 5% 4 5% 6% 21%	2309
	11th to 20th	Day	19% 17% 5% 9% 8% 3 4 5% 5% 6% 19%	2081
	21st to end	Day	23% 20% 7% 8% 5% 2 4 3 4 5% 19%	1980
October	1st to 10th	Day	18% 23% 8% 12% 6% 4 3 3 3 4 16%	1729
	11th to 20th	Day	18% 20% 11% 18% 7% 3 3 4 3 2 11%	1620
	21st to end	Day	17% 26% 9% 19% 10% 5% 5% 3 3 1 2	1540
November	1st to 10th	Day	13% 19% 9% 14% 15% 6% 9% 8% 4 2 2	1302
	11th to 20th	Day	9% 18% 7% 15% 11% 6% 9% 10% 5% 3 8%	1148
	21st to end	Day	7% 16% 10% 11% 12% 7% 11% 11% 6% 5% 5%	950
December	1st to 10th	Day	4 12% 7% 11% 12% 7% 11% 7% 13% 10% 7%	950
	11th to 20th	Day	4 10% 8% 14% 10% 9% 11% 10% 10% 7% 7%	1032
	21st to end	Day	6% 9% 6% 10% 11% 6% 9% 11% 12% 9% 12%	1386
January	1st to 10th	Night	4 10% 5% 10% 14% 10% 13% 10% 8% 10% 7%	5554
	11th to 20th	Night	3 11% 6% 12% 11% 9% 11% 13% 12% 9% 5%	5171
	21st to end	Night	7% 13% 6% 13% 10% 5% 7% 9% 11% 13% 6%	5566
February	1st to 10th	Night	2 6% 3 9% 9% 7% 12% 15% 12% 11% 13%	2766
	11th to 20th	Night	4 8% 3 8% 9% 5% 7% 10% 16% 15% 15%	2447
	21st to end	Night	2 7% 5% 11% 10% 6% 10% 12% 15% 10% 11%	2012
March	1st to 10th	Night	3 8% 4 10% 12% 5% 7% 8% 10% 12% 20%	2160
	11th to 20th	Night	7% 10% 5% 8% 8% 5% 9% 10% 8% 9% 23%	2088
	21st to end	Night	4 7% 4 9% 12% 6% 9% 8% 9% 9% 23%	2030
April	1st to 10th	Night	5% 10% 6% 11% 9% 5% 6% 11% 10% 6% 21%	1694
	11th to 20th	Night	8% 9% 6% 10% 7% 3 7% 6% 5% 6% 33%	1515
	21st to end	Night	8% 11% 4 10% 9% 5% 6% 5% 6% 6% 29%	1328
May	1st to 10th	Night	10% 9% 6% 14% 12% 5% 6% 5% 7% 6% 22%	1229
	11th to 20th	Night	11% 13% 6% 10% 9% 3 4 3 5% 8% 28%	990
	21st to end	Night	14% 11% 9% 11% 5% 3 3 5% 5% 8% 27%	970
June	1st to 10th	Night	22% 15% 6% 5% 5% 2 3 4 4 6% 29%	792
	11th to 20th	Night	13% 9% 3 8% 6% 3 6% 5% 6% 8% 33%	720
	21st to end	Night	10% 4 4 6% 7% 4 6% 6% 8% 7% 38%	720
July	1st to 10th	Night	15% 8% 3 7% 6% 3 7% 6% 5% 8% 33%	720
	11th to 20th	Night	15% 7% 3 5% 5% 3 5% 7% 7% 9% 34%	866
	21st to end	Night	12% 7% 3 6% 5% 3 4 4 6% 9% 41%	1147
August	1st to 10th	Night	16% 8% 3 7% 5% 4 5% 4 6% 6% 35%	1127
	11th to 20th	Night	18% 7% 3 7% 6% 4 6% 6% 7% 6% 30%	1331
	21st to end	Night	18% 8% 4 6% 7% 5% 5% 5% 5% 7% 30%	1647
September	1st to 10th	Night	22% 11% 3 7% 5% 3 5% 5% 4 6% 29%	1650
	11th to 20th	Night	20% 14% 6% 8% 7% 5% 5% 4 4 5% 21%	1879
	21st to end	Night	22% 16% 5% 8% 5% 3 4 5% 5% 6% 22%	1980
October	1st to 10th	Night	18% 22% 10% 12% 6% 3 4 3 4 4 14%	2212
	11th to 20th	Night	19% 19% 8% 17% 9% 3 4 3 3 3 12%	2340
	21st to end	Night	20% 25% 10% 18% 11% 5% 3 2 2 2 3	2813
November	1st to 10th	Night	13% 17% 9% 15% 13% 9% 9% 6% 3 3 4	2776
	11th to 20th	Night	9% 15% 6% 14% 11% 7% 10% 10% 6% 4 7%	3029
	21st to end	Night	8% 14% 7% 13% 12% 7% 10% 10% 9% 5% 5%	3230
December	1st to 10th	Night	4 12% 7% 13% 12% 7% 11% 12% 10% 8% 6%	3230
	11th to 20th	Night	4 11% 6% 12% 9% 7% 10% 12% 15% 7% 6%	4154
	21st to end	Night	7% 12% 5% 12% 13% 5% 8% 12% 10% 7% 8%	6270

Transparency (when cloud cover <= 30%)
Color Meanings: Too cloudy to forecast Poor Below Average Average Above average Transparent
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	66% 5% 9% 10% 8%	1391
	11th to 20th	Day	70% 7% 11% 11% 1	1741
	21st to end	Day	54% 5% 5% 21% 15%	2090
February	1st to 10th	Day	52% 6% 12% 18% 11%	1285
	11th to 20th	Day	48% 5% 15% 22% 10%	1408
	21st to end	Day	57% 7% 9% 17% 10%	1260
March	1st to 10th	Day	52% 6% 12% 21% 9% 1	1800
	11th to 20th	Day	56% 5% 11% 16% 12%	1872
	21st to end	Day	55% 6% 8% 19% 11% 1	2324
April	1st to 10th	Day	58% 6% 10% 17% 9% 1	2266
	11th to 20th	Day	60% 5% 8% 17% 8% 1	2394
	21st to end	Day	63% 6% 9% 16% 6%	2632
May	1st to 10th	Day	66% 6% 7% 16% 5%	2728
	11th to 20th	Day	62% 6% 8% 17% 6% 1	2907
	21st to end	Day	63% 6% 8% 19% 4	3306
June	1st to 10th	Day	58% 7% 10% 21% 5%	3164
	11th to 20th	Day	50% 8% 15% 20% 6%	3240
	21st to end	Day	43% 9% 13% 26% 8%	3240
July	1st to 10th	Day	49% 9% 14% 24% 4	3151
	11th to 20th	Day	44% 9% 17% 27% 3	2997
	21st to end	Day	41% 11% 14% 28% 4	2991
August	1st to 10th	Day	49% 9% 18% 20% 4	2793
	11th to 20th	Day	56% 10% 13% 18% 3	2568
	21st to end	Day	57% 9% 15% 18% 1	2709
September	1st to 10th	Day	64% 7% 14% 14% 1	2309
	11th to 20th	Day	66% 6% 17% 9% 1	2081
	21st to end	Day	70% 5% 12% 12% 2	1980
October	1st to 10th	Day	75% 5% 6% 11% 3 1	1729
	11th to 20th	Day	82% 4 5% 6% 4	1620
	21st to end	Day	91% 3 3 2	1540
November	1st to 10th	Day	87% 6% 5% 3	1302
	11th to 20th	Day	78% 6% 6% 9% 1	1148
	21st to end	Day	76% 5% 8% 9% 2	950
December	1st to 10th	Day	64% 7% 11% 16% 3	950
	11th to 20th	Day	69% 6% 9% 15% 2	1032
	21st to end	Day	59% 7% 14% 14% 6%	1386
January	1st to 10th	Night	69% 5% 8% 11% 7%	5554
	11th to 20th	Night	66% 8% 14% 11% 2	5216
	21st to end	Night	64% 4 6% 13% 13%	5566
February	1st to 10th	Night	50% 8% 14% 17% 10%	2766
	11th to 20th	Night	46% 6% 18% 20% 9%	2449
	21st to end	Night	54% 6% 10% 18% 11%	2012
March	1st to 10th	Night	50% 6% 13% 20% 10% 1	2160
	11th to 20th	Night	54% 5% 11% 19% 11%	2088
	21st to end	Night	53% 7% 7% 21% 10% 2	2030
April	1st to 10th	Night	54% 7% 10% 19% 10% 1	1694
	11th to 20th	Night	50% 6% 11% 22% 10% 1	1515
	21st to end	Night	54% 6% 10% 21% 9%	1328
May	1st to 10th	Night	60% 7% 8% 18% 6%	1229
	11th to 20th	Night	54% 5% 11% 19% 10% 1	990
	21st to end	Night	56% 6% 7% 26% 5%	970
June	1st to 10th	Night	57% 5% 12% 21% 5%	792
	11th to 20th	Night	48% 7% 15% 22% 7%	720
	21st to end	Night	41% 9% 17% 23% 9% 1	720
July	1st to 10th	Night	47% 7% 16% 25% 5%	700
	11th to 20th	Night	44% 10% 18% 24% 4	838
	21st to end	Night	37% 8% 18% 32% 5%	1083
August	1st to 10th	Night	47% 8% 19% 21% 4	1121
	11th to 20th	Night	51% 10% 16% 18% 4	1331
	21st to end	Night	52% 9% 17% 20% 2	1647
September	1st to 10th	Night	56% 9% 15% 17% 3	1650
	11th to 20th	Night	65% 8% 14% 11% 1	1879
	21st to end	Night	63% 8% 15% 12% 2	1980
October	1st to 10th	Night	75% 5% 8% 9% 2	2212
	11th to 20th	Night	80% 5% 6% 6% 3	2340
	21st to end	Night	92% 3 2 3 1	2813
November	1st to 10th	Night	86% 5% 5% 4	2776
	11th to 20th	Night	77% 7% 6% 8% 2	3029
	21st to end	Night	73% 7% 9% 10% 2	3230
December	1st to 10th	Night	68% 7% 9% 13% 3	3230
	11th to 20th	Night	62% 7% 9% 16% 6%	4154
	21st to end	Night	65% 5% 11% 14% 4	6270

Seeing (when cloud cover <= 80%)
Color Meanings: Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	8% 7% 23% 31% 27% 4	90
	11th to 20th	Day	13% 5% 29% 29% 18% 5%	136
	21st to end	Day	11% 5% 22% 31% 26% 5%	198
February	1st to 10th	Day	1 4 23% 41% 25% 7%	215
	11th to 20th	Day	9% 1 22% 41% 20% 7%	240
	21st to end	Day	5% 2 15% 38% 27% 14%	198
March	1st to 10th	Day	3 3 23% 33% 28% 11%	240
	11th to 20th	Day	10% 4 26% 29% 19% 13%	240
	21st to end	Day	7% 6% 22% 35% 24% 7%	410
April	1st to 10th	Day	10% 6% 21% 31% 24% 8%	526
	11th to 20th	Day	9% 4 19% 35% 25% 8%	590
	21st to end	Day	10% 3 20% 31% 27% 9%	600
May	1st to 10th	Day	14% 6% 19% 23% 25% 12%	603
	11th to 20th	Day	13% 5% 19% 30% 24% 9%	625
	21st to end	Day	18% 6% 22% 29% 19% 6%	679
June	1st to 10th	Day	29% 4 19% 24% 15% 9%	734
	11th to 20th	Day	19% 6% 19% 30% 20% 6%	810
	21st to end	Day	13% 5% 17% 32% 24% 9%	810
July	1st to 10th	Day	16% 5% 20% 27% 21% 11%	796
	11th to 20th	Day	14% 4 16% 29% 23% 13%	648
	21st to end	Day	14% 5% 12% 27% 28% 14%	684
August	1st to 10th	Day	19% 5% 15% 24% 23% 13%	626
	11th to 20th	Day	19% 5% 20% 24% 22% 9%	615
	21st to end	Day	24% 4 16% 26% 22% 9%	693
September	1st to 10th	Day	28% 8% 15% 24% 18% 7%	599
	11th to 20th	Day	21% 8% 17% 29% 15% 10%	371
	21st to end	Day	24% 6% 19% 28% 19% 4	270
October	1st to 10th	Day	21% 10% 25% 23% 14% 8%	270
	11th to 20th	Day	23% 9% 20% 25% 15% 7%	270
	21st to end	Day	24% 7% 22% 26% 16% 4	297
November	1st to 10th	Day	15% 4 26% 30% 19% 6%	270
	11th to 20th	Day	8% 5% 30% 40% 16% 1	183
	21st to end	Day	11% 8% 20% 29% 22% 10%	90
December	1st to 10th	Day	10% 6% 21% 36% 23% 4	90
	11th to 20th	Day	8% 1 21% 31% 22% 17%	90
	21st to end	Day	7% 15% 43% 26% 8%	99
January	1st to 10th	Night	10% 3 23% 35% 23% 6%	1002
	11th to 20th	Night	6% 4 27% 35% 23% 5%	950
	21st to end	Night	9% 5% 25% 38% 20% 2	1045
February	1st to 10th	Night	4 4 27% 38% 20% 7%	923
	11th to 20th	Night	7% 1 25% 41% 20% 5%	879
	21st to end	Night	5% 3 21% 39% 25% 7%	738
March	1st to 10th	Night	4 3 19% 39% 27% 8%	720
	11th to 20th	Night	12% 4 22% 34% 23% 5%	648
	21st to end	Night	7% 3 16% 40% 26% 7%	594
April	1st to 10th	Night	9% 4 25% 34% 24% 4	540
	11th to 20th	Night	10% 4 18% 35% 29% 5%	533
	21st to end	Night	13% 4 17% 38% 26% 3	540
May	1st to 10th	Night	13% 4 20% 29% 26% 8%	509
	11th to 20th	Night	16% 3 18% 33% 26% 5%	282
	21st to end	Night	19% 6% 15% 31% 29%	194
June	1st to 10th	Night	26% 8% 18% 26% 20% 2	180
	11th to 20th	Night	13% 7% 22% 34% 22% 2	180
	21st to end	Night	11% 3 21% 41% 23% 2	180
July	1st to 10th	Night	17% 4 22% 30% 27% 1	175
	11th to 20th	Night	13% 7% 16% 34% 27% 3	174
	21st to end	Night	14% 3 14% 31% 32% 5%	359
August	1st to 10th	Night	18% 5% 14% 29% 30% 4	411
	11th to 20th	Night	20% 3 19% 31% 26% 2	534
	21st to end	Night	21% 3 18% 31% 25% 2	594
September	1st to 10th	Night	26% 6% 19% 28% 16% 5%	540
	11th to 20th	Night	26% 5% 20% 30% 17% 2	540
	21st to end	Night	29% 5% 25% 28% 11% 3	540
October	1st to 10th	Night	26% 8% 24% 28% 11% 3	772
	11th to 20th	Night	29% 5% 19% 27% 17% 4	900
	21st to end	Night	32% 6% 21% 24% 14% 3	990
November	1st to 10th	Night	20% 5% 20% 29% 20% 5%	925
	11th to 20th	Night	15% 5% 28% 32% 17% 3	950
	21st to end	Night	16% 5% 23% 33% 18% 4	950
December	1st to 10th	Night	7% 3 23% 38% 23% 7%	950
	11th to 20th	Night	10% 3 23% 31% 26% 7%	1001
	21st to end	Night	10% 5% 20% 36% 23% 7%	1144

Page generated at 2024-02-02 04:20:29. Version ac07

Copyright 2024 Attilla Danko