Bunny Foo-Foo Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Bunny Foo-Foo Observatory clear sky chart from 2005-11-06 to 2026-08-15.

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% 6% 2 6% 4 4 4 4 6% 8% 42%	143716
	Night	14% 7% 2 6% 4 4 4 4 5% 7% 43%	138157
Transparency	Day	40% 5% 11% 24% 17% 4	147310
	Night	40% 4 10% 23% 18% 4	142635
Seeing	Day	20% 14% 29% 23% 11% 4	17325
	Night	18% 12% 30% 27% 11% 1	26790

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	14% 4 2 6% 4 4 5% 3 5% 6% 47%	4799
	11th to 20th	Day	15% 7% 2 6% 3 3 3 3 3 4 51%	5280
	21st to end	Day	13% 7% 2 6% 5% 4 4 3 5% 6% 44%	5780
February	1st to 10th	Day	14% 7% 2 7% 5% 4 5% 4 5% 6% 41%	1890
	11th to 20th	Day	20% 7% 2 5% 3 4 4 2 6% 6% 41%	1922
	21st to end	Day	18% 8% 2 7% 5% 3 3 3 5% 6% 40%	1730
March	1st to 10th	Day	19% 6% 2 5% 4 4 4 3 5% 8% 41%	4940
	11th to 20th	Day	11% 6% 2 5% 3 3 4 3 4 7% 51%	5090
	21st to end	Day	16% 6% 2 6% 4 4 4 4 5% 7% 41%	5712
April	1st to 10th	Day	13% 7% 2 6% 4 4 4 3 5% 7% 44%	2520
	11th to 20th	Day	12% 6% 2 5% 4 3 4 3 5% 6% 48%	2494
	21st to end	Day	17% 6% 2 5% 4 4 4 4 5% 7% 42%	2520
May	1st to 10th	Day	17% 7% 2 6% 4 4 4 4 6% 8% 36%	7395
	11th to 20th	Day	17% 6% 2 5% 4 4 5% 4 6% 9% 38%	8019
	21st to end	Day	21% 6% 2 6% 4 4 4 3 5% 7% 37%	9045
June	1st to 10th	Day	10% 5% 2 6% 5% 4 4 4 6% 10% 43%	2940
	11th to 20th	Day	10% 5% 2 6% 4 4 6% 5% 6% 9% 44%	2940
	21st to end	Day	9% 4 1 5% 4 5% 5% 5% 8% 10% 42%	2940
July	1st to 10th	Day	8% 6% 2 6% 4 4 5% 4 7% 10% 43%	8280
	11th to 20th	Day	9% 6% 2 8% 5% 6% 6% 5% 9% 13% 31%	8026
	21st to end	Day	8% 6% 2 7% 5% 6% 6% 6% 8% 10% 37%	8340
August	1st to 10th	Day	15% 7% 2 6% 4 5% 6% 5% 7% 10% 33%	4364
	11th to 20th	Day	10% 5% 2 7% 4 5% 6% 6% 8% 10% 38%	4010
	21st to end	Day	9% 5% 2 5% 4 4 5% 4 6% 9% 48%	4312
September	1st to 10th	Day	13% 5% 2 5% 4 4 4 4 5% 7% 47%	2400
	11th to 20th	Day	11% 6% 2 5% 3 4 4 4 6% 9% 46%	2400
	21st to end	Day	19% 8% 3 7% 4 4 4 3 5% 7% 36%	2111
October	1st to 10th	Day	15% 5% 2 5% 3 3 4 3 5% 7% 48%	2000
	11th to 20th	Day	16% 4 2 5% 3 3 2 3 4 6% 51%	2000
	21st to end	Day	13% 6% 2 6% 4 3 3 3 4 7% 49%	2200
November	1st to 10th	Day	12% 5% 1 3 4 3 4 4 4 7% 53%	1942
	11th to 20th	Day	13% 6% 1 4 3 3 4 3 5% 8% 50%	1890
	21st to end	Day	14% 6% 2 5% 4 3 3 3 5% 5% 49%	1687
December	1st to 10th	Day	12% 5% 2 6% 4 4 4 3 5% 7% 48%	2680
	11th to 20th	Day	17% 8% 2 5% 3 3 3 3 5% 7% 45%	3070
	21st to end	Day	15% 8% 3 6% 4 4 4 4 6% 8% 39%	4048
January	1st to 10th	Night	12% 7% 2 6% 4 4 5% 4 5% 6% 45%	8076
	11th to 20th	Night	14% 6% 2 5% 3 3 3 2 4 5% 52%	7680
	21st to end	Night	13% 8% 2 6% 4 3 4 3 4 6% 48%	8401
February	1st to 10th	Night	15% 7% 2 6% 4 4 4 3 5% 7% 42%	2730
	11th to 20th	Night	20% 7% 3 5% 3 3 3 3 4 6% 43%	2582
	21st to end	Night	16% 8% 2 5% 4 4 3 3 5% 6% 43%	2076
March	1st to 10th	Night	16% 7% 2 5% 3 4 3 3 5% 5% 47%	5130
	11th to 20th	Night	11% 5% 2 5% 3 3 4 3 6% 7% 50%	5090
	21st to end	Night	13% 7% 2 7% 4 4 4 3 5% 6% 44%	5461
April	1st to 10th	Night	15% 7% 2 5% 5% 4 4 4 5% 7% 41%	2100
	11th to 20th	Night	13% 5% 2 5% 4 4 4 4 5% 7% 47%	2075
	21st to end	Night	16% 5% 2 5% 3 3 5% 4 6% 8% 43%	2100
May	1st to 10th	Night	16% 8% 3 7% 5% 4 5% 4 6% 8% 33%	5500
	11th to 20th	Night	18% 7% 3 6% 4 4 5% 4 6% 8% 37%	4825
	21st to end	Night	22% 8% 2 7% 4 4 4 4 5% 8% 33%	5108
June	1st to 10th	Night	9% 5% 2 5% 4 4 5% 5% 8% 10% 43%	1680
	11th to 20th	Night	12% 6% 2 6% 5% 4 5% 4 7% 11% 39%	1680
	21st to end	Night	9% 5% 2 5% 5% 4 5% 4 8% 9% 43%	1680
July	1st to 10th	Night	10% 7% 2 8% 5% 5% 5% 4 7% 9% 39%	4678
	11th to 20th	Night	10% 9% 3 9% 6% 6% 6% 5% 6% 10% 30%	4913
	21st to end	Night	9% 7% 3 7% 5% 6% 5% 5% 8% 9% 37%	5736
August	1st to 10th	Night	16% 6% 2 8% 5% 5% 5% 4 6% 10% 33%	3005
	11th to 20th	Night	11% 8% 3 9% 5% 5% 6% 5% 7% 8% 33%	3093
	21st to end	Night	9% 5% 2 5% 4 3 4 3 6% 7% 51%	3586
September	1st to 10th	Night	13% 5% 2 7% 3 4 5% 3 5% 8% 46%	2000
	11th to 20th	Night	10% 6% 2 6% 3 3 4 4 5% 8% 48%	2000
	21st to end	Night	19% 9% 2 6% 5% 3 3 4 5% 7% 37%	2283
October	1st to 10th	Night	16% 7% 2 6% 3 3 4 3 4 6% 47%	2400
	11th to 20th	Night	15% 5% 2 5% 3 3 3 3 4 6% 52%	2400
	21st to end	Night	14% 4 2 5% 3 3 4 3 5% 7% 50%	2640
November	1st to 10th	Night	12% 5% 2 4 4 3 3 3 5% 6% 53%	2574
	11th to 20th	Night	15% 7% 2 4 4 3 3 3 4 6% 48%	2730
	21st to end	Night	13% 5% 2 4 4 3 4 4 5% 7% 49%	2930
December	1st to 10th	Night	10% 6% 2 5% 3 3 3 3 5% 7% 53%	4720
	11th to 20th	Night	20% 7% 2 5% 4 3 4 3 4 6% 41%	5345
	21st to end	Night	16% 7% 2 6% 4 4 5% 4 5% 7% 40%	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	40% 2 6% 26% 20% 5%	4800
	11th to 20th	Day	39% 2 5% 21% 24% 9%	5280
	21st to end	Day	41% 4 7% 32% 14% 3	5780
February	1st to 10th	Day	43% 5% 11% 25% 13% 2	1890
	11th to 20th	Day	44% 4 8% 23% 18% 3	1931
	21st to end	Day	46% 5% 11% 19% 16% 4	1730
March	1st to 10th	Day	42% 3 8% 21% 18% 8%	4940
	11th to 20th	Day	34% 4 9% 26% 22% 6%	5090
	21st to end	Day	43% 4 10% 18% 18% 7%	5712
April	1st to 10th	Day	39% 5% 11% 21% 19% 5%	2520
	11th to 20th	Day	36% 5% 10% 23% 20% 6%	2494
	21st to end	Day	41% 5% 10% 23% 17% 4	2520
May	1st to 10th	Day	46% 5% 11% 21% 16% 1	7428
	11th to 20th	Day	43% 6% 10% 27% 14% 1	8023
	21st to end	Day	47% 5% 9% 19% 17% 3	9061
June	1st to 10th	Day	35% 8% 13% 26% 17% 2	2940
	11th to 20th	Day	35% 9% 13% 24% 17% 2	2940
	21st to end	Day	33% 9% 15% 24% 17% 2	2940
July	1st to 10th	Day	37% 5% 20% 21% 13% 3	8210
	11th to 20th	Day	44% 5% 15% 25% 9% 1	7951
	21st to end	Day	42% 5% 11% 22% 20% 1	8156
August	1st to 10th	Day	45% 6% 15% 26% 7%	4351
	11th to 20th	Day	41% 6% 13% 26% 14% 1	4049
	21st to end	Day	33% 5% 13% 28% 18% 2	4312
September	1st to 10th	Day	37% 6% 13% 20% 20% 4	2400
	11th to 20th	Day	35% 6% 9% 26% 20% 3	2400
	21st to end	Day	48% 5% 9% 19% 16% 3	2111
October	1st to 10th	Day	38% 4 6% 18% 29% 5%	3260
	11th to 20th	Day	27% 2 6% 29% 26% 10%	3240
	21st to end	Day	23% 3 7% 30% 26% 10%	3538
November	1st to 10th	Day	31% 5% 10% 28% 21% 5%	1942
	11th to 20th	Day	34% 4 10% 25% 22% 5%	1890
	21st to end	Day	37% 4 9% 29% 19% 3	1687
December	1st to 10th	Day	37% 3 12% 27% 17% 4	2680
	11th to 20th	Day	41% 3 13% 29% 11% 3	3066
	21st to end	Day	43% 5% 13% 23% 16% 1	4048
January	1st to 10th	Night	39% 3 8% 25% 21% 4	8077
	11th to 20th	Night	36% 2 5% 23% 24% 8%	7680
	21st to end	Night	40% 2 6% 29% 20% 3	8401
February	1st to 10th	Night	42% 4 11% 24% 17% 2	2730
	11th to 20th	Night	44% 3 8% 21% 18% 5%	2584
	21st to end	Night	42% 3 10% 22% 17% 6%	2076
March	1st to 10th	Night	39% 4 7% 24% 17% 9%	5130
	11th to 20th	Night	33% 4 10% 24% 21% 7%	5090
	21st to end	Night	41% 4 8% 22% 20% 6%	5461
April	1st to 10th	Night	42% 4 10% 20% 20% 5%	2100
	11th to 20th	Night	36% 5% 11% 22% 21% 5%	2075
	21st to end	Night	39% 5% 10% 24% 16% 5%	2100
May	1st to 10th	Night	49% 4 11% 21% 11% 2	5530
	11th to 20th	Night	45% 4 12% 25% 13% 1	4826
	21st to end	Night	50% 5% 10% 17% 15% 2	5115
June	1st to 10th	Night	35% 9% 11% 25% 18% 2	1680
	11th to 20th	Night	39% 7% 14% 24% 13% 2	1680
	21st to end	Night	35% 8% 14% 21% 19% 3	1680
July	1st to 10th	Night	43% 7% 15% 20% 13% 2	4640
	11th to 20th	Night	49% 6% 17% 19% 9% 1	4868
	21st to end	Night	43% 4 14% 22% 16% 1	5606
August	1st to 10th	Night	47% 6% 17% 22% 8%	2994
	11th to 20th	Night	47% 5% 11% 24% 12% 1	3120
	21st to end	Night	33% 5% 10% 30% 21% 2	3586
September	1st to 10th	Night	37% 7% 10% 23% 18% 6%	2000
	11th to 20th	Night	34% 6% 9% 27% 21% 3	2000
	21st to end	Night	47% 7% 10% 18% 16% 3	2283
October	1st to 10th	Night	41% 3 9% 21% 20% 6%	3920
	11th to 20th	Night	25% 3 10% 22% 32% 9%	3899
	21st to end	Night	23% 3 9% 31% 26% 9%	4252
November	1st to 10th	Night	33% 5% 9% 25% 23% 6%	2574
	11th to 20th	Night	38% 4 9% 21% 22% 7%	2730
	21st to end	Night	34% 4 11% 26% 22% 4	2930
December	1st to 10th	Night	33% 3 12% 28% 22% 3	4720
	11th to 20th	Night	45% 3 11% 20% 16% 5%	5348
	21st to end	Night	43% 5% 13% 22% 15% 1	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	31% 23% 29% 11% 4	245
	11th to 20th	Day	32% 25% 29% 12% 1	330
	21st to end	Day	23% 31% 33% 11% 2	363
February	1st to 10th	Day	25% 27% 34% 10% 3	330
	11th to 20th	Day	38% 21% 31% 9% 1	409
	21st to end	Day	31% 23% 30% 14% 2	446
March	1st to 10th	Day	24% 24% 33% 16% 3 1	540
	11th to 20th	Day	28% 23% 31% 14% 4 1	540
	21st to end	Day	24% 20% 36% 16% 4 1	594
April	1st to 10th	Day	23% 23% 32% 16% 5% 1	540
	11th to 20th	Day	19% 21% 33% 17% 8% 2	532
	21st to end	Day	24% 15% 34% 19% 6% 1	540
May	1st to 10th	Day	26% 19% 29% 16% 8% 2	543
	11th to 20th	Day	21% 17% 30% 22% 9% 1	567
	21st to end	Day	22% 10% 26% 25% 14% 3	617
June	1st to 10th	Day	12% 11% 31% 26% 17% 4	570
	11th to 20th	Day	15% 9% 30% 29% 14% 3	570
	21st to end	Day	12% 7% 31% 31% 16% 3	570
July	1st to 10th	Day	12% 3 20% 36% 20% 9%	565
	11th to 20th	Day	5% 3 18% 44% 22% 8%	564
	21st to end	Day	11% 3 24% 36% 20% 7%	620
August	1st to 10th	Day	12% 5% 24% 33% 19% 6%	566
	11th to 20th	Day	14% 3 21% 35% 20% 7%	535
	21st to end	Day	10% 4 23% 33% 20% 11%	583
September	1st to 10th	Day	16% 6% 24% 27% 15% 12%	530
	11th to 20th	Day	14% 5% 24% 33% 15% 9%	530
	21st to end	Day	27% 11% 25% 23% 10% 3	530
October	1st to 10th	Day	19% 9% 24% 25% 16% 6%	530
	11th to 20th	Day	18% 15% 29% 25% 12% 2	530
	21st to end	Day	17% 16% 35% 21% 9% 2	583
November	1st to 10th	Day	16% 15% 36% 22% 8% 3	474
	11th to 20th	Day	21% 17% 32% 21% 7% 2	430
	21st to end	Day	26% 20% 30% 14% 9%	227
December	1st to 10th	Day	21% 23% 39% 11% 5% 1	220
	11th to 20th	Day	25% 21% 31% 19% 4	220
	21st to end	Day	28% 19% 29% 20% 3	242
January	1st to 10th	Night	21% 22% 37% 16% 4	840
	11th to 20th	Night	24% 18% 32% 21% 4	840
	21st to end	Night	21% 19% 39% 19% 2	924
February	1st to 10th	Night	21% 17% 36% 24% 3	840
	11th to 20th	Night	27% 23% 35% 14% 1	823
	21st to end	Night	24% 21% 35% 17% 2	692
March	1st to 10th	Night	21% 18% 38% 21% 2	840
	11th to 20th	Night	23% 18% 36% 17% 5%	840
	21st to end	Night	20% 17% 41% 18% 3	924
April	1st to 10th	Night	21% 22% 36% 18% 3	840
	11th to 20th	Night	17% 16% 36% 26% 5%	831
	21st to end	Night	20% 13% 34% 25% 8%	840
May	1st to 10th	Night	19% 13% 34% 25% 8% 1	727
	11th to 20th	Night	18% 9% 34% 32% 7%	485
	21st to end	Night	17% 5% 27% 34% 16% 1	455
June	1st to 10th	Night	10% 5% 28% 37% 19% 1	420
	11th to 20th	Night	13% 6% 24% 40% 15% 1	420
	21st to end	Night	11% 2 28% 41% 16% 1	420
July	1st to 10th	Night	10% 2 21% 40% 25% 1	410
	11th to 20th	Night	7% 2 15% 46% 26% 4	488
	21st to end	Night	9% 1 23% 38% 26% 3	690
August	1st to 10th	Night	11% 2 16% 42% 26% 3	627
	11th to 20th	Night	13% 2 19% 41% 23% 2	710
	21st to end	Night	13% 2 19% 35% 27% 4	880
September	1st to 10th	Night	16% 3 19% 33% 25% 4	800
	11th to 20th	Night	13% 3 17% 39% 25% 4	800
	21st to end	Night	23% 7% 23% 30% 17% 1	800
October	1st to 10th	Night	19% 7% 22% 30% 18% 6%	800
	11th to 20th	Night	17% 13% 26% 27% 16% 1	800
	21st to end	Night	17% 12% 34% 26% 11% 1	880
November	1st to 10th	Night	15% 11% 35% 28% 10% 2	820
	11th to 20th	Night	21% 16% 30% 25% 8%	840
	21st to end	Night	17% 17% 32% 25% 9% 1	840
December	1st to 10th	Night	21% 16% 34% 21% 7% 1	840
	11th to 20th	Night	20% 16% 36% 23% 5%	840
	21st to end	Night	21% 14% 35% 28% 3	924

Page generated at 2026-08-12 03:37:19. Version ac07

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