Vivekananda Monastery
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Vivekananda Monastery clear sky chart from 2005-11-06 to 2026-04-17.

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	14% 11% 4 9% 5% 4 4 3 5% 6% 34%	131204
	Night	15% 14% 5% 11% 5% 4 4 3 4 5% 29%	131206
Transparency	Day	49% 6% 11% 21% 12% 1	134743
	Night	56% 5% 10% 17% 11% 1	135742
Seeing	Day	18% 14% 28% 25% 12% 3	17722
	Night	21% 13% 26% 26% 12% 1	27702

By Month

Percentage Cloud Cover SE (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	15% 24% 13% 22% 5% 3 3 2 2 3 9%	4691
	11th to 20th	Day	9% 17% 9% 25% 14% 10% 3 2 2 2 6%	4710
	21st to end	Day	14% 17% 7% 19% 13% 5% 7% 2 3 3 12%	5156
February	1st to 10th	Day	13% 17% 6% 16% 10% 6% 4 2 4 3 18%	1949
	11th to 20th	Day	14% 15% 7% 17% 8% 5% 3 3 4 4 21%	2048
	21st to end	Day	15% 15% 6% 14% 6% 4 5% 4 4 6% 22%	1730
March	1st to 10th	Day	14% 11% 5% 11% 5% 4 4 3 5% 6% 32%	4580
	11th to 20th	Day	11% 10% 6% 8% 4 4 4 3 6% 8% 36%	4894
	21st to end	Day	20% 13% 7% 9% 5% 4 4 3 4 5% 26%	5881
April	1st to 10th	Day	19% 12% 3 6% 5% 4 4 4 5% 6% 30%	2520
	11th to 20th	Day	17% 10% 3 6% 4 3 4 4 5% 6% 38%	2471
	21st to end	Day	17% 9% 3 7% 4 4 4 3 7% 7% 36%	2600
May	1st to 10th	Day	18% 7% 3 6% 4 4 4 3 6% 8% 39%	5862
	11th to 20th	Day	14% 7% 2 5% 4 4 4 3 6% 8% 43%	5922
	21st to end	Day	15% 6% 2 5% 3 3 4 3 5% 8% 46%	6935
June	1st to 10th	Day	10% 5% 2 5% 4 4 4 3 6% 7% 49%	2800
	11th to 20th	Day	9% 5% 2 5% 4 4 5% 4 5% 9% 48%	2800
	21st to end	Day	11% 6% 2 5% 4 4 4 3 6% 7% 47%	2800
July	1st to 10th	Day	12% 6% 2 6% 4 4 4 4 6% 9% 43%	6360
	11th to 20th	Day	8% 5% 2 5% 3 4 4 4 6% 9% 51%	6360
	21st to end	Day	8% 6% 2 5% 4 4 4 4 6% 9% 48%	6924
August	1st to 10th	Day	11% 5% 2 5% 4 3 4 3 5% 9% 48%	4309
	11th to 20th	Day	11% 5% 2 5% 3 4 4 3 5% 7% 51%	4145
	21st to end	Day	8% 6% 3 5% 4 4 4 4 5% 9% 50%	4312
September	1st to 10th	Day	11% 7% 2 5% 4 4 5% 3 5% 8% 47%	2390
	11th to 20th	Day	12% 5% 2 4 3 4 4 3 6% 8% 50%	2200
	21st to end	Day	13% 6% 2 7% 5% 5% 4 3 5% 8% 42%	2200
October	1st to 10th	Day	17% 6% 2 6% 4 4 4 2 4 6% 45%	2200
	11th to 20th	Day	23% 11% 2 8% 5% 5% 4 4 6% 6% 27%	1950
	21st to end	Day	26% 11% 3 8% 5% 5% 5% 4 4 5% 24%	1980
November	1st to 10th	Day	14% 15% 3 6% 4 4 4 4 4 6% 35%	1852
	11th to 20th	Day	17% 24% 4 9% 5% 4 5% 3 4 5% 21%	1890
	21st to end	Day	23% 20% 7% 9% 4 4 3 3 3 4 19%	1890
December	1st to 10th	Day	13% 29% 12% 13% 4 3 3 2 3 4 14%	2735
	11th to 20th	Day	16% 27% 13% 13% 7% 3 3 2 3 3 9%	3088
	21st to end	Day	25% 23% 8% 14% 4 4 3 2 3 4 11%	4070
January	1st to 10th	Night	13% 24% 12% 23% 5% 3 2 2 2 3 11%	8232
	11th to 20th	Night	12% 21% 13% 24% 9% 8% 2 1 2 2 6%	8280
	21st to end	Night	14% 19% 8% 19% 10% 8% 5% 2 2 3 10%	9058
February	1st to 10th	Night	13% 19% 6% 17% 9% 4 4 2 3 3 19%	2665
	11th to 20th	Night	14% 17% 8% 15% 7% 4 3 3 4 4 21%	2458
	21st to end	Night	18% 15% 4 13% 6% 4 3 3 4 5% 25%	2076
March	1st to 10th	Night	16% 10% 5% 10% 4 4 4 3 4 6% 34%	5493
	11th to 20th	Night	11% 10% 3 8% 4 3 4 2 5% 7% 42%	5285
	21st to end	Night	18% 13% 5% 10% 4 4 3 3 4 6% 30%	5321
April	1st to 10th	Night	16% 11% 3 6% 5% 4 5% 5% 5% 6% 34%	2100
	11th to 20th	Night	20% 10% 3 6% 4 3 4 4 5% 6% 36%	2009
	21st to end	Night	16% 7% 3 6% 4 4 4 4 6% 7% 38%	1800
May	1st to 10th	Night	17% 10% 3 8% 5% 5% 4 3 5% 6% 34%	4033
	11th to 20th	Night	17% 7% 2 6% 4 4 5% 3 5% 7% 42%	3959
	21st to end	Night	17% 7% 3 6% 3 4 4 3 5% 6% 42%	3942
June	1st to 10th	Night	11% 5% 2 5% 5% 4 4 5% 6% 8% 45%	1600
	11th to 20th	Night	10% 6% 2 6% 5% 4 4 5% 6% 8% 43%	1600
	21st to end	Night	10% 5% 2 6% 5% 4 5% 4 6% 9% 44%	1600
July	1st to 10th	Night	10% 6% 2 6% 5% 4 5% 4 6% 9% 43%	3618
	11th to 20th	Night	8% 4 2 5% 4 4 4 4 5% 8% 51%	3617
	21st to end	Night	10% 5% 2 6% 4 4 5% 3 6% 9% 46%	3947
August	1st to 10th	Night	9% 4 2 6% 4 4 4 4 6% 8% 48%	2842
	11th to 20th	Night	12% 5% 2 5% 3 4 4 3 5% 6% 51%	2901
	21st to end	Night	9% 6% 2 7% 4 5% 4 3 6% 7% 47%	3586
September	1st to 10th	Night	10% 5% 2 6% 4 4 5% 3 4 7% 50%	2000
	11th to 20th	Night	11% 3 2 3 4 4 4 4 5% 6% 53%	2190
	21st to end	Night	13% 7% 3 8% 5% 4 4 3 5% 7% 42%	2200
October	1st to 10th	Night	17% 5% 2 5% 4 3 4 3 4 6% 46%	2200
	11th to 20th	Night	22% 10% 3 7% 5% 3 3 3 4 6% 34%	2449
	21st to end	Night	28% 11% 3 6% 4 3 4 2 4 5% 31%	2860
November	1st to 10th	Night	18% 13% 4 7% 5% 4 4 3 4 6% 33%	2666
	11th to 20th	Night	18% 21% 6% 9% 4 4 4 2 5% 5% 23%	2730
	21st to end	Night	20% 22% 6% 9% 4 4 3 2 3 5% 21%	2730
December	1st to 10th	Night	14% 28% 9% 15% 5% 4 3 2 3 3 13%	4670
	11th to 20th	Night	18% 27% 10% 14% 6% 3 3 2 3 4 9%	5339
	21st to end	Night	25% 23% 7% 11% 4 4 4 3 4 5% 11%	7150

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	83% 4 5% 6% 1	4692
	11th to 20th	Day	87% 3 6% 3 1	4710
	21st to end	Day	78% 5% 7% 7% 2	5156
February	1st to 10th	Day	72% 6% 8% 11% 3	1949
	11th to 20th	Day	67% 5% 10% 13% 5%	2058
	21st to end	Day	63% 7% 12% 12% 5%	1730
March	1st to 10th	Day	51% 6% 14% 18% 9% 1	4580
	11th to 20th	Day	45% 6% 17% 23% 9% 1	4894
	21st to end	Day	60% 6% 9% 16% 9% 1	5883
April	1st to 10th	Day	53% 7% 9% 19% 11%	2520
	11th to 20th	Day	46% 7% 10% 22% 13% 3	2471
	21st to end	Day	45% 7% 13% 20% 14% 2	2600
May	1st to 10th	Day	42% 7% 13% 22% 15% 1	5897
	11th to 20th	Day	38% 8% 14% 24% 15% 2	5926
	21st to end	Day	35% 7% 11% 27% 18% 1	6949
June	1st to 10th	Day	33% 7% 11% 28% 19% 2	2800
	11th to 20th	Day	31% 8% 14% 26% 20% 2	2800
	21st to end	Day	34% 8% 15% 23% 18% 2	2800
July	1st to 10th	Day	38% 5% 12% 28% 15% 2	6291
	11th to 20th	Day	30% 6% 13% 31% 19% 1	6285
	21st to end	Day	32% 6% 16% 25% 19% 2	6728
August	1st to 10th	Day	33% 6% 13% 32% 15% 1	4294
	11th to 20th	Day	31% 7% 13% 32% 15% 1	4184
	21st to end	Day	31% 6% 14% 28% 18% 2	4311
September	1st to 10th	Day	35% 6% 13% 28% 14% 3	2390
	11th to 20th	Day	31% 5% 13% 31% 17% 2	2200
	21st to end	Day	39% 5% 14% 26% 16%	2200
October	1st to 10th	Day	30% 4 8% 40% 17% 1	3590
	11th to 20th	Day	43% 6% 11% 24% 17%	3153
	21st to end	Day	53% 4 12% 21% 9% 1	3180
November	1st to 10th	Day	49% 7% 13% 19% 12%	1852
	11th to 20th	Day	67% 4 9% 14% 5% 1	1890
	21st to end	Day	69% 6% 11% 11% 3	1890
December	1st to 10th	Day	77% 5% 11% 6% 1	2735
	11th to 20th	Day	80% 6% 7% 6% 1	3085
	21st to end	Day	79% 3 6% 9% 2	4070
January	1st to 10th	Night	81% 3 7% 7% 2	8233
	11th to 20th	Night	88% 2 5% 3 1	8280
	21st to end	Night	82% 4 7% 5% 2	9058
February	1st to 10th	Night	71% 5% 8% 11% 5%	2665
	11th to 20th	Night	67% 5% 7% 15% 5%	2459
	21st to end	Night	62% 5% 11% 14% 7% 1	2076
March	1st to 10th	Night	50% 6% 13% 23% 8% 1	5493
	11th to 20th	Night	41% 5% 13% 28% 10% 2	5285
	21st to end	Night	57% 5% 9% 18% 11% 1	5321
April	1st to 10th	Night	48% 8% 12% 19% 14% 1	2100
	11th to 20th	Night	49% 5% 9% 17% 17% 3	2009
	21st to end	Night	43% 8% 13% 19% 15% 3	1800
May	1st to 10th	Night	49% 6% 11% 16% 14% 3	4060
	11th to 20th	Night	42% 7% 11% 21% 16% 3	3960
	21st to end	Night	42% 6% 8% 21% 20% 2	3950
June	1st to 10th	Night	34% 7% 11% 28% 17% 3	1600
	11th to 20th	Night	37% 7% 12% 24% 18% 3	1600
	21st to end	Night	35% 6% 16% 24% 16% 3	1600
July	1st to 10th	Night	37% 4 12% 28% 14% 5%	3580
	11th to 20th	Night	31% 5% 14% 25% 23% 3	3572
	21st to end	Night	35% 6% 13% 21% 23% 2	3832
August	1st to 10th	Night	32% 6% 14% 29% 18% 1	2833
	11th to 20th	Night	33% 6% 10% 32% 18% 1	2928
	21st to end	Night	36% 5% 10% 27% 20% 2	3586
September	1st to 10th	Night	34% 6% 14% 26% 17% 3	2000
	11th to 20th	Night	31% 5% 10% 32% 21% 2	2190
	21st to end	Night	42% 6% 11% 24% 16% 1	2200
October	1st to 10th	Night	30% 4 9% 34% 22% 2	3590
	11th to 20th	Night	42% 4 12% 22% 20%	3985
	21st to end	Night	48% 3 9% 25% 15%	4610
November	1st to 10th	Night	53% 5% 10% 19% 12% 1	2666
	11th to 20th	Night	63% 5% 10% 15% 6% 1	2730
	21st to end	Night	67% 5% 12% 15% 2	2730
December	1st to 10th	Night	78% 4 9% 6% 2	4670
	11th to 20th	Night	81% 4 9% 5% 1	5341
	21st to end	Night	76% 5% 9% 7% 3	7150

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	24% 24% 29% 19% 4 1	330
	11th to 20th	Day	26% 22% 37% 12% 3	330
	21st to end	Day	29% 20% 34% 16% 1	363
February	1st to 10th	Day	23% 28% 30% 14% 4 1	330
	11th to 20th	Day	24% 28% 34% 13% 1	330
	21st to end	Day	24% 32% 35% 8% 1	273
March	1st to 10th	Day	19% 27% 38% 13% 2	330
	11th to 20th	Day	23% 22% 31% 17% 6%	448
	21st to end	Day	26% 20% 31% 18% 5% 1	594
April	1st to 10th	Day	26% 18% 35% 17% 4	540
	11th to 20th	Day	23% 22% 31% 16% 5% 3	516
	21st to end	Day	21% 18% 31% 20% 8% 1	500
May	1st to 10th	Day	20% 17% 32% 23% 6% 2	503
	11th to 20th	Day	16% 11% 30% 28% 11% 4	549
	21st to end	Day	13% 9% 31% 29% 15% 4	789
June	1st to 10th	Day	12% 8% 32% 32% 13% 3	730
	11th to 20th	Day	13% 8% 26% 37% 14% 3	730
	21st to end	Day	11% 9% 32% 31% 14% 2	730
July	1st to 10th	Day	9% 6% 22% 34% 23% 6%	721
	11th to 20th	Day	10% 6% 25% 37% 16% 5%	718
	21st to end	Day	7% 5% 25% 39% 19% 5%	794
August	1st to 10th	Day	9% 5% 20% 31% 25% 10%	576
	11th to 20th	Day	11% 5% 23% 33% 21% 8%	519
	21st to end	Day	11% 6% 19% 34% 24% 6%	583
September	1st to 10th	Day	14% 8% 22% 30% 21% 6%	530
	11th to 20th	Day	8% 6% 18% 29% 28% 11%	530
	21st to end	Day	16% 13% 19% 26% 18% 7%	530
October	1st to 10th	Day	18% 13% 23% 26% 18% 2	530
	11th to 20th	Day	27% 18% 26% 24% 6%	400
	21st to end	Day	32% 16% 34% 15% 3 1	363
November	1st to 10th	Day	26% 17% 30% 21% 6%	330
	11th to 20th	Day	32% 25% 27% 14% 2	330
	21st to end	Day	33% 18% 38% 9% 2	330
December	1st to 10th	Day	29% 26% 25% 15% 5%	330
	11th to 20th	Day	26% 30% 29% 12% 2	330
	21st to end	Day	30% 25% 31% 10% 2 1	363
January	1st to 10th	Night	25% 22% 32% 18% 4	1050
	11th to 20th	Night	28% 20% 31% 18% 2 1	1050
	21st to end	Night	24% 17% 34% 22% 3	1155
February	1st to 10th	Night	22% 18% 34% 21% 5%	895
	11th to 20th	Night	22% 19% 32% 23% 4	823
	21st to end	Night	26% 18% 34% 19% 3	692
March	1st to 10th	Night	22% 16% 31% 23% 6% 1	840
	11th to 20th	Night	19% 16% 33% 25% 6% 1	840
	21st to end	Night	23% 13% 30% 28% 6%	812
April	1st to 10th	Night	19% 16% 33% 25% 7% 1	630
	11th to 20th	Night	25% 12% 28% 26% 8% 1	611
	21st to end	Night	18% 14% 28% 30% 9% 1	600
May	1st to 10th	Night	20% 7% 28% 34% 10% 2	600
	11th to 20th	Night	20% 8% 23% 34% 14% 1	591
	21st to end	Night	14% 5% 24% 33% 23% 2	650
June	1st to 10th	Night	12% 5% 23% 41% 19% 1	600
	11th to 20th	Night	11% 4 28% 35% 21% 1	600
	21st to end	Night	12% 5% 21% 36% 23% 3	600
July	1st to 10th	Night	9% 3 15% 37% 32% 3	585
	11th to 20th	Night	9% 3 17% 40% 28% 4	582
	21st to end	Night	9% 2 16% 42% 29% 3	657
August	1st to 10th	Night	9% 2 13% 42% 30% 5%	597
	11th to 20th	Night	13% 4 11% 40% 26% 6%	594
	21st to end	Night	9% 5% 17% 37% 29% 3	660
September	1st to 10th	Night	12% 5% 17% 36% 25% 5%	600
	11th to 20th	Night	11% 5% 16% 31% 31% 5%	790
	21st to end	Night	17% 9% 22% 28% 20% 5%	800
October	1st to 10th	Night	19% 7% 22% 32% 19% 1	800
	11th to 20th	Night	28% 14% 25% 24% 9% 1	800
	21st to end	Night	34% 13% 26% 21% 5%	880
November	1st to 10th	Night	26% 16% 28% 21% 9% 1	820
	11th to 20th	Night	30% 20% 27% 18% 4	840
	21st to end	Night	33% 15% 30% 18% 3	840
December	1st to 10th	Night	31% 20% 29% 16% 3	1013
	11th to 20th	Night	30% 20% 32% 16% 2	1050
	21st to end	Night	35% 18% 31% 14% 2	1155

Page generated at 2026-04-14 02:44:24. Version ac07

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