Punxsutawney
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Punxsutawney clear sky chart from 2005-11-05 to 2024-10-14.

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	17% 12% 4 9% 5% 5% 4 4 5% 7% 30%	101022
	Night	17% 12% 5% 9% 5% 4 4 3 5% 6% 30%	97433
Transparency	Day	53% 6% 11% 19% 9% 1	100826
	Night	54% 6% 11% 19% 10% 1	97305
Seeing	Day	24% 16% 28% 19% 10% 4	14624
	Night	23% 14% 27% 25% 10% 1	24148

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	17% 21% 12% 16% 4 3 3 1 3 3 16%	2627
	11th to 20th	Day	11% 20% 10% 20% 9% 5% 3 2 3 3 14%	2840
	21st to end	Day	26% 19% 10% 16% 6% 4 3 2 3 3 10%	3124
February	1st to 10th	Day	18% 20% 5% 11% 9% 6% 4 2 3 4 18%	1710
	11th to 20th	Day	16% 14% 7% 15% 8% 5% 4 3 4 5% 19%	1663
	21st to end	Day	20% 17% 4 12% 5% 4 4 3 5% 5% 21%	1545
March	1st to 10th	Day	20% 12% 5% 8% 4 4 4 3 4 7% 28%	3435
	11th to 20th	Day	12% 16% 7% 10% 5% 5% 4 3 4 5% 29%	3480
	21st to end	Day	17% 11% 3 9% 6% 5% 4 4 5% 6% 31%	3815
April	1st to 10th	Day	16% 16% 3 7% 5% 4 4 5% 5% 7% 28%	2244
	11th to 20th	Day	17% 13% 3 7% 5% 4 4 3 5% 6% 33%	2254
	21st to end	Day	21% 12% 3 7% 5% 4 3 3 6% 6% 31%	2437
May	1st to 10th	Day	25% 10% 3 7% 5% 4 4 4 6% 6% 27%	4082
	11th to 20th	Day	21% 10% 3 7% 5% 5% 5% 4 6% 7% 27%	4203
	21st to end	Day	14% 7% 2 6% 4 5% 5% 4 6% 8% 39%	4823
June	1st to 10th	Day	16% 7% 3 7% 5% 5% 6% 4 7% 7% 32%	2660
	11th to 20th	Day	15% 8% 3 7% 5% 5% 5% 4 7% 9% 34%	2660
	21st to end	Day	15% 6% 2 6% 5% 5% 6% 4 6% 10% 35%	2660
July	1st to 10th	Day	10% 7% 2 7% 5% 6% 6% 5% 6% 9% 37%	4440
	11th to 20th	Day	11% 6% 3 6% 5% 6% 6% 4 7% 9% 37%	4232
	21st to end	Day	11% 8% 3 8% 6% 6% 5% 4 6% 7% 37%	4466
August	1st to 10th	Day	17% 10% 4 8% 6% 6% 5% 4 6% 7% 27%	4104
	11th to 20th	Day	13% 8% 3 8% 5% 6% 7% 4 7% 8% 33%	4044
	21st to end	Day	11% 6% 2 7% 5% 5% 5% 5% 8% 10% 37%	4229
September	1st to 10th	Day	17% 7% 3 6% 4 4 3 3 5% 6% 43%	2280
	11th to 20th	Day	13% 7% 2 6% 4 4 4 3 7% 8% 42%	2183
	21st to end	Day	21% 9% 3 6% 4 3 4 3 5% 7% 33%	2038
October	1st to 10th	Day	18% 8% 3 6% 5% 4 4 3 6% 7% 35%	1900
	11th to 20th	Day	22% 10% 3 7% 4 4 4 4 5% 6% 32%	1830
	21st to end	Day	25% 12% 3 7% 4 4 5% 3 4 5% 29%	1980
November	1st to 10th	Day	12% 10% 3 7% 5% 5% 3 3 6% 7% 38%	1792
	11th to 20th	Day	18% 16% 4 8% 5% 4 4 3 5% 5% 28%	1520
	21st to end	Day	20% 18% 6% 7% 5% 4 4 3 5% 6% 22%	1520
December	1st to 10th	Day	20% 23% 8% 13% 5% 4 3 3 4 4 14%	1520
	11th to 20th	Day	18% 22% 7% 12% 4 3 3 3 4 5% 19%	1910
	21st to end	Day	27% 24% 7% 10% 4 3 3 2 3 3 13%	2772
January	1st to 10th	Night	15% 22% 10% 15% 5% 4 4 3 4 4 16%	4301
	11th to 20th	Night	15% 18% 9% 17% 6% 7% 5% 3 3 3 14%	4120
	21st to end	Night	26% 17% 9% 14% 5% 3 3 2 3 4 15%	4532
February	1st to 10th	Night	18% 15% 5% 13% 8% 6% 4 3 3 4 22%	2470
	11th to 20th	Night	17% 14% 5% 13% 6% 5% 5% 3 4 5% 22%	2403
	21st to end	Night	20% 13% 4 11% 5% 5% 5% 4 4 4 25%	1903
March	1st to 10th	Night	23% 12% 3 7% 4 4 4 3 4 6% 31%	3418
	11th to 20th	Night	15% 14% 9% 8% 5% 3 3 3 4 6% 30%	3480
	21st to end	Night	16% 11% 3 7% 4 4 4 3 4 6% 38%	3817
April	1st to 10th	Night	17% 15% 5% 7% 5% 4 4 3 4 6% 30%	1934
	11th to 20th	Night	16% 11% 3 7% 4 4 5% 3 4 6% 37%	1875
	21st to end	Night	15% 11% 2 8% 6% 4 4 3 5% 6% 35%	1759
May	1st to 10th	Night	28% 10% 2 6% 4 3 4 4 4 6% 28%	2813
	11th to 20th	Night	20% 11% 3 8% 4 4 4 3 5% 6% 32%	2687
	21st to end	Night	13% 8% 3 5% 4 4 5% 4 7% 10% 37%	2732
June	1st to 10th	Night	10% 7% 2 7% 5% 5% 3 4 5% 9% 43%	1520
	11th to 20th	Night	12% 6% 2 7% 6% 5% 5% 4 7% 8% 39%	1520
	21st to end	Night	13% 6% 3 5% 4 5% 4 4 7% 9% 40%	1520
July	1st to 10th	Night	13% 8% 3 7% 5% 4 5% 4 5% 7% 39%	2520
	11th to 20th	Night	11% 6% 2 7% 5% 5% 5% 4 7% 8% 41%	2710
	21st to end	Night	12% 8% 3 8% 5% 5% 5% 3 6% 7% 40%	3087
August	1st to 10th	Night	16% 10% 3 6% 4 5% 5% 4 6% 7% 34%	2825
	11th to 20th	Night	16% 7% 2 7% 4 4 5% 4 5% 8% 39%	2785
	21st to end	Night	9% 5% 2 6% 4 5% 5% 4 6% 9% 45%	3380
September	1st to 10th	Night	14% 7% 2 4 3 3 5% 4 5% 6% 47%	1900
	11th to 20th	Night	11% 5% 2 5% 3 4 4 3 5% 8% 51%	1993
	21st to end	Night	18% 8% 3 7% 4 4 4 3 4 7% 37%	2142
October	1st to 10th	Night	17% 6% 3 6% 4 4 3 3 5% 7% 41%	2280
	11th to 20th	Night	19% 9% 2 7% 5% 4 4 3 6% 6% 37%	2203
	21st to end	Night	24% 11% 3 7% 5% 4 4 4 5% 5% 31%	2376
November	1st to 10th	Night	13% 11% 3 5% 5% 3 4 4 4 6% 42%	2279
	11th to 20th	Night	17% 15% 4 7% 5% 5% 5% 4 5% 6% 28%	2660
	21st to end	Night	18% 15% 5% 9% 5% 4 4 4 5% 5% 26%	2660
December	1st to 10th	Night	21% 18% 8% 11% 6% 4 3 4 4 5% 15%	2660
	11th to 20th	Night	19% 17% 7% 13% 6% 4 4 3 3 4 21%	3285
	21st to end	Night	22% 20% 8% 11% 6% 5% 4 3 4 4 13%	4884

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	75% 3 7% 10% 4 1	2628
	11th to 20th	Day	76% 3 7% 10% 3	2840
	21st to end	Day	80% 4 6% 7% 2 1	3124
February	1st to 10th	Day	72% 4 8% 11% 5%	1710
	11th to 20th	Day	67% 5% 10% 13% 6%	1672
	21st to end	Day	65% 4 11% 13% 6% 1	1545
March	1st to 10th	Day	54% 6% 11% 24% 5%	3435
	11th to 20th	Day	55% 7% 15% 17% 5% 1	3480
	21st to end	Day	51% 7% 11% 19% 11% 1	3815
April	1st to 10th	Day	54% 7% 10% 16% 11% 2	2244
	11th to 20th	Day	51% 5% 11% 16% 14% 2	2254
	21st to end	Day	52% 6% 9% 20% 12% 1	2437
May	1st to 10th	Day	55% 7% 9% 20% 7% 1	4120
	11th to 20th	Day	55% 7% 12% 17% 8% 1	4207
	21st to end	Day	39% 9% 14% 23% 12% 2	4837
June	1st to 10th	Day	47% 9% 12% 21% 11% 1	2660
	11th to 20th	Day	46% 8% 14% 20% 12% 1	2660
	21st to end	Day	44% 7% 12% 25% 12%	2660
July	1st to 10th	Day	42% 8% 12% 24% 13% 2	4370
	11th to 20th	Day	40% 8% 13% 25% 13%	4159
	21st to end	Day	43% 7% 11% 21% 17% 1	4324
August	1st to 10th	Day	53% 8% 13% 19% 7%	4091
	11th to 20th	Day	44% 8% 13% 26% 8% 1	4083
	21st to end	Day	38% 8% 14% 26% 12% 1	4229
September	1st to 10th	Day	43% 6% 9% 23% 17% 3	2280
	11th to 20th	Day	38% 7% 12% 25% 16% 1	2183
	21st to end	Day	49% 6% 12% 20% 13% 1	2038
October	1st to 10th	Day	46% 6% 12% 20% 13% 1	1900
	11th to 20th	Day	52% 6% 11% 22% 8%	1831
	21st to end	Day	58% 5% 11% 16% 9% 1	1980
November	1st to 10th	Day	44% 7% 12% 19% 16% 2	1792
	11th to 20th	Day	57% 5% 10% 18% 8% 2	1520
	21st to end	Day	63% 5% 11% 15% 6% 1	1520
December	1st to 10th	Day	74% 5% 9% 9% 3	1520
	11th to 20th	Day	68% 4 10% 15% 3	1906
	21st to end	Day	77% 4 8% 9% 2	2772
January	1st to 10th	Night	72% 5% 7% 12% 3	4301
	11th to 20th	Night	74% 5% 10% 9% 2	4120
	21st to end	Night	75% 4 7% 10% 3 1	4532
February	1st to 10th	Night	67% 4 9% 15% 6%	2470
	11th to 20th	Night	65% 4 9% 15% 6%	2405
	21st to end	Night	62% 6% 8% 15% 9% 1	1903
March	1st to 10th	Night	55% 5% 10% 23% 7%	3418
	11th to 20th	Night	54% 7% 13% 19% 6% 1	3480
	21st to end	Night	45% 6% 10% 22% 15% 2	3817
April	1st to 10th	Night	55% 5% 10% 17% 13% 1	1934
	11th to 20th	Night	48% 6% 12% 19% 14% 3	1875
	21st to end	Night	48% 6% 9% 22% 12% 2	1759
May	1st to 10th	Night	55% 7% 9% 17% 11% 2	2840
	11th to 20th	Night	51% 9% 11% 20% 8% 1	2688
	21st to end	Night	37% 11% 14% 22% 12% 4	2739
June	1st to 10th	Night	37% 8% 14% 26% 13% 2	1520
	11th to 20th	Night	40% 8% 13% 24% 13% 2	1520
	21st to end	Night	39% 9% 13% 24% 14% 1	1520
July	1st to 10th	Night	44% 7% 11% 20% 17% 2	2480
	11th to 20th	Night	37% 8% 16% 23% 15% 1	2661
	21st to end	Night	42% 7% 11% 18% 20% 2	2988
August	1st to 10th	Night	47% 8% 14% 22% 9%	2814
	11th to 20th	Night	42% 6% 13% 28% 10% 1	2812
	21st to end	Night	34% 8% 14% 31% 12% 2	3380
September	1st to 10th	Night	37% 7% 12% 24% 18% 3	1900
	11th to 20th	Night	31% 6% 12% 28% 21% 1	1993
	21st to end	Night	47% 5% 11% 20% 15% 1	2142
October	1st to 10th	Night	42% 7% 12% 23% 14% 2	2280
	11th to 20th	Night	47% 5% 13% 22% 11% 1	2207
	21st to end	Night	55% 5% 10% 19% 10% 1	2376
November	1st to 10th	Night	42% 6% 12% 20% 16% 3	2279
	11th to 20th	Night	56% 5% 10% 17% 9% 2	2660
	21st to end	Night	59% 6% 10% 18% 6% 1	2660
December	1st to 10th	Night	71% 6% 9% 10% 4	2660
	11th to 20th	Night	68% 4 10% 14% 4	3288
	21st to end	Night	73% 6% 10% 9% 2	4884

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	35% 27% 24% 9% 4	213
	11th to 20th	Day	34% 31% 25% 7% 2	270
	21st to end	Day	32% 24% 33% 9% 2	297
February	1st to 10th	Day	33% 27% 31% 7% 2	270
	11th to 20th	Day	37% 28% 29% 6%	270
	21st to end	Day	37% 27% 27% 9% 1	305
March	1st to 10th	Day	31% 23% 30% 13% 3	460
	11th to 20th	Day	33% 20% 30% 11% 4 1	460
	21st to end	Day	34% 22% 24% 14% 4 1	506
April	1st to 10th	Day	29% 23% 27% 16% 4 1	460
	11th to 20th	Day	27% 22% 27% 13% 7% 3	452
	21st to end	Day	30% 19% 30% 15% 5% 1	460
May	1st to 10th	Day	30% 17% 27% 16% 7% 2	463
	11th to 20th	Day	25% 14% 32% 17% 9% 3	487
	21st to end	Day	18% 11% 26% 26% 15% 5%	529
June	1st to 10th	Day	18% 17% 27% 25% 11% 2	490
	11th to 20th	Day	19% 12% 27% 24% 14% 4	490
	21st to end	Day	19% 13% 31% 23% 11% 2	490
July	1st to 10th	Day	15% 8% 25% 24% 17% 10%	485
	11th to 20th	Day	13% 8% 27% 31% 15% 7%	484
	21st to end	Day	14% 7% 30% 28% 15% 6%	532
August	1st to 10th	Day	14% 7% 22% 31% 18% 8%	486
	11th to 20th	Day	15% 7% 26% 26% 16% 10%	479
	21st to end	Day	14% 9% 25% 26% 17% 9%	539
September	1st to 10th	Day	18% 7% 24% 25% 17% 9%	490
	11th to 20th	Day	12% 6% 22% 31% 21% 8%	490
	21st to end	Day	26% 13% 24% 19% 12% 5%	490
October	1st to 10th	Day	21% 13% 23% 22% 15% 5%	490
	11th to 20th	Day	26% 15% 32% 19% 7% 1	462
	21st to end	Day	33% 16% 29% 16% 6%	495
November	1st to 10th	Day	22% 16% 28% 20% 13% 1	412
	11th to 20th	Day	29% 22% 32% 13% 3 1	180
	21st to end	Day	27% 23% 40% 9% 1	180
December	1st to 10th	Day	37% 24% 27% 8% 2 1	180
	11th to 20th	Day	39% 19% 33% 6% 3	180
	21st to end	Day	41% 21% 27% 8% 3	198
January	1st to 10th	Night	29% 23% 33% 11% 3	760
	11th to 20th	Night	33% 21% 29% 15% 2	760
	21st to end	Night	28% 22% 31% 16% 2	836
February	1st to 10th	Night	30% 20% 29% 19% 1	760
	11th to 20th	Night	30% 23% 34% 11% 1	743
	21st to end	Night	31% 23% 28% 16% 2	628
March	1st to 10th	Night	26% 20% 32% 19% 3	760
	11th to 20th	Night	29% 20% 26% 18% 6% 1	760
	21st to end	Night	25% 16% 36% 18% 5% 1	836
April	1st to 10th	Night	26% 18% 30% 21% 5%	760
	11th to 20th	Night	23% 17% 30% 21% 8% 1	751
	21st to end	Night	21% 13% 34% 27% 5%	619
May	1st to 10th	Night	23% 12% 26% 30% 8% 1	570
	11th to 20th	Night	22% 10% 29% 30% 10%	488
	21st to end	Night	12% 6% 27% 31% 22% 1	411
June	1st to 10th	Night	14% 4 28% 40% 13% 1	380
	11th to 20th	Night	13% 6% 24% 41% 14%	380
	21st to end	Night	12% 5% 30% 41% 13% 1	380
July	1st to 10th	Night	14% 4 19% 42% 18% 3	370
	11th to 20th	Night	12% 4 19% 39% 23% 3	479
	21st to end	Night	14% 3 18% 42% 22% 1	624
August	1st to 10th	Night	13% 2 18% 42% 23% 2	567
	11th to 20th	Night	15% 5% 15% 36% 26% 3	564
	21st to end	Night	12% 4 19% 37% 24% 4	779
September	1st to 10th	Night	17% 6% 19% 32% 22% 3	760
	11th to 20th	Night	13% 5% 18% 34% 26% 4	760
	21st to end	Night	21% 10% 22% 27% 16% 4	760
October	1st to 10th	Night	19% 9% 22% 29% 18% 2	760
	11th to 20th	Night	24% 13% 29% 25% 7% 1	735
	21st to end	Night	30% 14% 27% 24% 4	792
November	1st to 10th	Night	20% 13% 29% 28% 9%	740
	11th to 20th	Night	29% 16% 28% 21% 6% 1	760
	21st to end	Night	27% 19% 30% 19% 5%	760
December	1st to 10th	Night	33% 21% 28% 14% 4	760
	11th to 20th	Night	29% 24% 26% 16% 4	760
	21st to end	Night	31% 22% 27% 18% 2	836

Page generated at 2024-10-11 10:49:56. Version ac07

Copyright © 2024 Attilla Danko.