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 2025-04-11.

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%	113499
	Night	14% 7% 2 6% 4 4 4 3 5% 7% 45%	114791
Transparency	Day	39% 5% 11% 24% 17% 4	117136
	Night	38% 5% 10% 23% 19% 4	119294
Seeing	Day	19% 14% 29% 23% 11% 4	15514
	Night	18% 12% 30% 27% 11% 1	25161

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% 4 1 4 4 4 4 3 5% 6% 51%	3707
	11th to 20th	Day	15% 8% 3 6% 3 3 3 3 4 5% 47%	4060
	21st to end	Day	15% 8% 2 6% 5% 4 4 3 5% 5% 43%	4466
February	1st to 10th	Day	15% 8% 2 7% 5% 4 5% 4 5% 6% 40%	1800
	11th to 20th	Day	20% 6% 2 5% 3 4 4 2 6% 6% 41%	1828
	21st to end	Day	18% 8% 2 7% 5% 3 3 3 5% 6% 40%	1650
March	1st to 10th	Day	19% 6% 2 5% 3 4 4 4 5% 8% 42%	4833
	11th to 20th	Day	11% 6% 2 5% 3 3 4 3 4 7% 51%	4980
	21st to end	Day	17% 6% 2 6% 5% 4 4 4 5% 6% 41%	5589
April	1st to 10th	Day	14% 7% 2 6% 4 4 4 4 5% 7% 43%	2400
	11th to 20th	Day	13% 6% 2 5% 4 3 4 3 5% 6% 48%	2254
	21st to end	Day	17% 6% 3 5% 4 3 4 4 5% 6% 42%	2280
May	1st to 10th	Day	23% 8% 3 7% 4 4 4 4 6% 8% 29%	3973
	11th to 20th	Day	21% 7% 2 6% 5% 4 5% 4 6% 8% 31%	4292
	21st to end	Day	10% 5% 2 6% 4 4 5% 4 7% 8% 45%	4823
June	1st to 10th	Day	11% 5% 2 6% 5% 4 4 5% 7% 10% 42%	2660
	11th to 20th	Day	10% 5% 2 6% 4 4 6% 5% 6% 9% 44%	2660
	21st to end	Day	9% 4 1 5% 4 5% 5% 5% 8% 10% 42%	2660
July	1st to 10th	Day	6% 4 1 6% 5% 5% 6% 5% 9% 11% 42%	4440
	11th to 20th	Day	10% 6% 2 6% 5% 4 5% 5% 8% 12% 37%	4298
	21st to end	Day	10% 7% 2 7% 6% 5% 6% 6% 7% 9% 35%	4466
August	1st to 10th	Day	15% 7% 2 6% 4 5% 6% 5% 7% 10% 32%	4104
	11th to 20th	Day	9% 5% 2 7% 4 5% 6% 6% 8% 9% 38%	3835
	21st to end	Day	9% 5% 2 5% 4 4 5% 4 6% 9% 47%	4180
September	1st to 10th	Day	13% 5% 2 5% 4 4 5% 4 5% 7% 46%	2280
	11th to 20th	Day	10% 6% 2 6% 3 4 4 3 6% 9% 46%	2280
	21st to end	Day	19% 8% 3 6% 4 4 4 3 5% 7% 36%	2006
October	1st to 10th	Day	15% 5% 2 5% 3 3 4 3 5% 6% 47%	1900
	11th to 20th	Day	16% 4 2 4 3 3 2 3 4 6% 51%	1900
	21st to end	Day	13% 6% 2 6% 4 3 3 3 4 7% 49%	2090
November	1st to 10th	Day	12% 5% 1 3 4 3 4 4 4 7% 53%	1848
	11th to 20th	Day	14% 6% 1 4 3 3 4 3 5% 8% 50%	1800
	21st to end	Day	13% 6% 2 5% 4 3 3 3 5% 5% 50%	1607
December	1st to 10th	Day	11% 5% 2 6% 4 4 4 3 5% 7% 48%	2600
	11th to 20th	Day	18% 8% 2 5% 3 3 3 3 5% 6% 44%	2990
	21st to end	Day	15% 8% 3 6% 4 4 4 4 6% 8% 39%	3960
January	1st to 10th	Night	13% 7% 2 5% 3 3 4 3 4 5% 50%	6234
	11th to 20th	Night	13% 6% 2 5% 3 3 3 2 4 6% 53%	5900
	21st to end	Night	14% 9% 2 6% 4 3 3 3 3 5% 47%	6490
February	1st to 10th	Night	16% 7% 2 5% 4 4 4 3 5% 7% 42%	2600
	11th to 20th	Night	20% 7% 2 5% 3 3 3 3 4 5% 44%	2456
	21st to end	Night	17% 8% 2 5% 3 4 3 3 5% 6% 44%	1980
March	1st to 10th	Night	16% 7% 2 5% 3 4 3 3 5% 5% 47%	5017
	11th to 20th	Night	11% 5% 2 5% 3 3 4 3 6% 7% 50%	4980
	21st to end	Night	14% 7% 2 7% 4 4 4 3 5% 6% 45%	5342
April	1st to 10th	Night	16% 7% 2 5% 5% 4 4 4 5% 7% 41%	2000
	11th to 20th	Night	13% 5% 2 5% 4 3 3 3 5% 7% 48%	1882
	21st to end	Night	17% 6% 2 5% 3 3 5% 4 6% 8% 42%	1900
May	1st to 10th	Night	20% 10% 3 7% 4 4 5% 4 6% 7% 32%	2950
	11th to 20th	Night	21% 8% 3 7% 4 4 4 3 5% 7% 34%	2599
	21st to end	Night	9% 5% 2 6% 4 4 5% 4 6% 11% 43%	2732
June	1st to 10th	Night	10% 5% 2 5% 4 4 5% 4 8% 10% 42%	1520
	11th to 20th	Night	11% 6% 2 6% 5% 4 4 4 7% 11% 40%	1520
	21st to end	Night	9% 5% 2 5% 5% 4 5% 4 8% 9% 43%	1520
July	1st to 10th	Night	6% 5% 2 8% 5% 6% 6% 5% 8% 10% 41%	2520
	11th to 20th	Night	8% 7% 2 7% 5% 5% 5% 5% 6% 11% 38%	2644
	21st to end	Night	10% 7% 3 8% 5% 6% 5% 5% 7% 8% 35%	3087
August	1st to 10th	Night	16% 6% 2 8% 5% 5% 5% 4 6% 10% 33%	2825
	11th to 20th	Night	10% 8% 3 9% 5% 5% 6% 5% 7% 8% 34%	2962
	21st to end	Night	9% 5% 2 5% 4 3 4 3 5% 7% 52%	3476
September	1st to 10th	Night	13% 5% 2 7% 3 4 5% 3 5% 8% 45%	1900
	11th to 20th	Night	9% 6% 2 6% 4 3 4 4 6% 8% 48%	1900
	21st to end	Night	18% 9% 2 6% 5% 3 3 4 5% 7% 38%	2168
October	1st to 10th	Night	16% 6% 2 6% 3 3 4 3 4 6% 46%	2280
	11th to 20th	Night	15% 5% 2 5% 3 3 3 3 4 6% 52%	2280
	21st to end	Night	14% 4 2 5% 3 3 4 3 5% 7% 50%	2508
November	1st to 10th	Night	12% 5% 2 4 4 3 3 3 4 6% 53%	2448
	11th to 20th	Night	16% 7% 2 4 4 3 3 4 4 6% 48%	2600
	21st to end	Night	13% 5% 2 4 4 3 4 4 5% 7% 49%	2790
December	1st to 10th	Night	10% 6% 2 5% 3 3 3 3 5% 7% 53%	4580
	11th to 20th	Night	20% 7% 2 5% 4 4 4 3 4 7% 40%	5205
	21st to end	Night	16% 7% 2 6% 4 4 5% 4 5% 7% 39%	6996

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	36% 3 5% 27% 23% 6%	3708
	11th to 20th	Day	41% 3 6% 21% 21% 8%	4060
	21st to end	Day	43% 5% 8% 27% 14% 3	4466
February	1st to 10th	Day	44% 5% 11% 25% 12% 2	1800
	11th to 20th	Day	44% 4 8% 24% 18% 3	1837
	21st to end	Day	45% 5% 11% 19% 16% 4	1650
March	1st to 10th	Day	42% 3 8% 22% 18% 8%	4833
	11th to 20th	Day	34% 4 9% 25% 22% 6%	4980
	21st to end	Day	44% 4 10% 18% 18% 7%	5589
April	1st to 10th	Day	40% 6% 10% 21% 18% 6%	2400
	11th to 20th	Day	36% 6% 9% 22% 20% 7%	2254
	21st to end	Day	41% 6% 10% 22% 17% 4	2280
May	1st to 10th	Day	51% 8% 10% 19% 11% 1	4009
	11th to 20th	Day	48% 9% 12% 22% 9% 1	4296
	21st to end	Day	33% 10% 13% 25% 17% 3	4837
June	1st to 10th	Day	35% 9% 13% 26% 15% 1	2660
	11th to 20th	Day	35% 10% 12% 24% 16% 2	2660
	21st to end	Day	33% 9% 15% 24% 17% 2	2660
July	1st to 10th	Day	34% 7% 23% 19% 12% 5%	4370
	11th to 20th	Day	38% 5% 18% 27% 10% 1	4223
	21st to end	Day	43% 8% 12% 20% 17% 1	4324
August	1st to 10th	Day	46% 6% 16% 25% 7%	4091
	11th to 20th	Day	40% 6% 12% 27% 14% 1	3874
	21st to end	Day	33% 5% 14% 28% 17% 2	4180
September	1st to 10th	Day	38% 7% 12% 19% 20% 4	2280
	11th to 20th	Day	35% 6% 9% 26% 20% 4	2280
	21st to end	Day	47% 6% 9% 19% 16% 3	2006
October	1st to 10th	Day	39% 4 6% 17% 29% 5%	3160
	11th to 20th	Day	26% 3 6% 29% 26% 11%	3140
	21st to end	Day	23% 3 8% 30% 26% 10%	3428
November	1st to 10th	Day	32% 5% 10% 28% 21% 5%	1848
	11th to 20th	Day	34% 4 10% 25% 22% 5%	1800
	21st to end	Day	36% 4 9% 28% 20% 3	1607
December	1st to 10th	Day	37% 3 12% 27% 18% 4	2600
	11th to 20th	Day	41% 3 13% 28% 11% 3	2986
	21st to end	Day	43% 5% 13% 22% 16% 1	3960
January	1st to 10th	Night	37% 3 5% 24% 25% 5%	6234
	11th to 20th	Night	35% 3 6% 25% 24% 7%	5900
	21st to end	Night	41% 3 7% 27% 20% 3	6490
February	1st to 10th	Night	42% 5% 12% 24% 16% 2	2600
	11th to 20th	Night	44% 3 8% 21% 19% 5%	2458
	21st to end	Night	42% 3 10% 22% 17% 6%	1980
March	1st to 10th	Night	39% 4 6% 24% 18% 9%	5017
	11th to 20th	Night	33% 4 10% 24% 21% 7%	4980
	21st to end	Night	41% 4 7% 22% 20% 6%	5342
April	1st to 10th	Night	42% 4 10% 19% 20% 5%	2000
	11th to 20th	Night	36% 5% 11% 21% 21% 5%	1882
	21st to end	Night	40% 6% 10% 24% 15% 5%	1900
May	1st to 10th	Night	50% 7% 11% 19% 10% 2	2980
	11th to 20th	Night	49% 8% 11% 21% 9% 2	2600
	21st to end	Night	32% 9% 16% 24% 15% 3	2739
June	1st to 10th	Night	34% 9% 11% 26% 17% 2	1520
	11th to 20th	Night	38% 7% 15% 25% 13% 3	1520
	21st to end	Night	34% 8% 15% 20% 19% 3	1520
July	1st to 10th	Night	38% 8% 22% 18% 12% 3	2480
	11th to 20th	Night	40% 7% 20% 23% 9% 1	2596
	21st to end	Night	44% 7% 14% 21% 14% 1	2988
August	1st to 10th	Night	47% 7% 17% 22% 8%	2814
	11th to 20th	Night	46% 6% 11% 24% 12% 1	2989
	21st to end	Night	33% 5% 10% 30% 21% 2	3476
September	1st to 10th	Night	37% 7% 10% 21% 18% 6%	1900
	11th to 20th	Night	33% 6% 9% 26% 22% 3	1900
	21st to end	Night	45% 7% 9% 18% 17% 3	2168
October	1st to 10th	Night	41% 3 9% 21% 19% 6%	3800
	11th to 20th	Night	24% 3 10% 21% 32% 9%	3779
	21st to end	Night	22% 3 9% 31% 26% 9%	4120
November	1st to 10th	Night	33% 5% 9% 25% 22% 6%	2448
	11th to 20th	Night	38% 4 9% 21% 22% 7%	2600
	21st to end	Night	34% 5% 11% 25% 22% 4	2790
December	1st to 10th	Night	33% 3 11% 28% 22% 3	4580
	11th to 20th	Night	46% 3 11% 20% 15% 5%	5208
	21st to end	Night	43% 5% 13% 22% 16% 1	6996

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	32% 24% 29% 11% 4	223
	11th to 20th	Day	32% 24% 30% 13% 1	300
	21st to end	Day	22% 30% 33% 12% 2	330
February	1st to 10th	Day	24% 28% 35% 9% 3	300
	11th to 20th	Day	38% 22% 30% 9% 1	375
	21st to end	Day	31% 23% 30% 14% 2	414
March	1st to 10th	Day	24% 25% 33% 16% 2 1	500
	11th to 20th	Day	28% 22% 31% 14% 4 1	500
	21st to end	Day	24% 20% 35% 17% 4 1	550
April	1st to 10th	Day	24% 24% 32% 15% 5% 1	500
	11th to 20th	Day	17% 21% 32% 18% 8% 2	452
	21st to end	Day	24% 16% 35% 18% 6% 1	460
May	1st to 10th	Day	26% 18% 27% 18% 9% 2	463
	11th to 20th	Day	21% 16% 30% 22% 9% 1	487
	21st to end	Day	17% 9% 28% 27% 16% 4	529
June	1st to 10th	Day	12% 11% 29% 26% 18% 4	490
	11th to 20th	Day	13% 9% 29% 29% 17% 3	490
	21st to end	Day	11% 8% 32% 31% 15% 3	490
July	1st to 10th	Day	11% 4 21% 36% 20% 8%	485
	11th to 20th	Day	5% 3 18% 44% 22% 8%	484
	21st to end	Day	11% 3 24% 35% 19% 7%	532
August	1st to 10th	Day	12% 5% 24% 32% 21% 6%	486
	11th to 20th	Day	13% 3 21% 34% 21% 8%	479
	21st to end	Day	10% 4 22% 33% 21% 11%	539
September	1st to 10th	Day	16% 6% 22% 27% 16% 13%	490
	11th to 20th	Day	14% 5% 24% 33% 15% 10%	490
	21st to end	Day	26% 12% 25% 23% 10% 3	490
October	1st to 10th	Day	20% 9% 24% 25% 17% 5%	490
	11th to 20th	Day	16% 15% 28% 26% 12% 2	490
	21st to end	Day	17% 14% 36% 22% 9% 3	539
November	1st to 10th	Day	16% 14% 35% 23% 9% 3	440
	11th to 20th	Day	20% 18% 33% 21% 7% 2	400
	21st to end	Day	25% 21% 30% 14% 10%	207
December	1st to 10th	Day	20% 24% 40% 11% 5% 1	200
	11th to 20th	Day	26% 21% 30% 20% 4	200
	21st to end	Day	26% 20% 29% 21% 4	220
January	1st to 10th	Night	21% 22% 37% 15% 4	800
	11th to 20th	Night	24% 18% 32% 22% 4	800
	21st to end	Night	20% 20% 39% 20% 2	880
February	1st to 10th	Night	21% 17% 36% 23% 3	800
	11th to 20th	Night	27% 23% 34% 14% 1	783
	21st to end	Night	24% 21% 36% 17% 2	660
March	1st to 10th	Night	21% 18% 37% 22% 2	800
	11th to 20th	Night	22% 18% 36% 17% 6%	800
	21st to end	Night	20% 16% 41% 18% 3	880
April	1st to 10th	Night	21% 22% 36% 18% 3	800
	11th to 20th	Night	17% 16% 35% 26% 6%	754
	21st to end	Night	21% 13% 33% 25% 8%	760
May	1st to 10th	Night	19% 12% 33% 26% 9% 1	658
	11th to 20th	Night	18% 9% 33% 32% 8%	439
	21st to end	Night	15% 4 26% 36% 17% 1	411
June	1st to 10th	Night	11% 4 28% 37% 19% 1	380
	11th to 20th	Night	12% 5% 23% 42% 16% 1	380
	21st to end	Night	11% 2 28% 43% 14% 1	380
July	1st to 10th	Night	10% 2 22% 39% 25% 1	370
	11th to 20th	Night	6% 2 15% 45% 27% 4	440
	21st to end	Night	9% 1 23% 38% 26% 3	624
August	1st to 10th	Night	10% 2 16% 43% 26% 3	567
	11th to 20th	Night	12% 2 19% 41% 23% 2	663
	21st to end	Night	13% 2 18% 36% 27% 4	836
September	1st to 10th	Night	17% 3 18% 34% 25% 4	760
	11th to 20th	Night	12% 3 17% 39% 26% 4	760
	21st to end	Night	22% 7% 24% 29% 17% 1	760
October	1st to 10th	Night	19% 7% 22% 30% 17% 5%	760
	11th to 20th	Night	16% 12% 26% 28% 16% 1	760
	21st to end	Night	17% 12% 33% 26% 12% 1	836
November	1st to 10th	Night	14% 10% 36% 28% 10% 2	780
	11th to 20th	Night	20% 16% 30% 25% 8% 1	800
	21st to end	Night	17% 17% 32% 24% 9% 1	800
December	1st to 10th	Night	22% 16% 34% 21% 8% 1	800
	11th to 20th	Night	20% 16% 37% 23% 5%	800
	21st to end	Night	21% 14% 34% 28% 3	880

Page generated at 2025-04-08 09:17:26. Version ac07

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