Rexburg Nature Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Rexburg Nature Park clear sky chart from 2005-11-06 to 2024-02-25.

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	9% 9% 3 6% 5% 3 4 4 5% 7% 46%	78350
	Night	11% 11% 4 7% 5% 3 4 4 4 6% 42%	80952
Transparency	Day	39% 5% 11% 21% 16% 8%	78056
	Night	44% 5% 12% 20% 13% 6%	80766
Seeing	Day	13% 9% 23% 30% 20% 6%	14300
	Night	15% 5% 19% 40% 19% 2	24094

By Month

Percentage Cloud Cover SW (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	12% 22% 8% 10% 5% 3 4 4 4 5% 22%	2393
	11th to 20th	Day	14% 16% 6% 10% 7% 4 4 3 4 5% 26%	2608
	21st to end	Day	17% 22% 6% 11% 5% 2 3 3 3 4 25%	3146
February	1st to 10th	Day	15% 16% 5% 10% 6% 3 5% 5% 4 5% 26%	1710
	11th to 20th	Day	14% 15% 6% 10% 6% 3 4 4 5% 6% 27%	1665
	21st to end	Day	10% 14% 7% 10% 7% 3 4 4 5% 6% 29%	1516
March	1st to 10th	Day	9% 14% 5% 8% 6% 4 5% 4 5% 7% 34%	1898
	11th to 20th	Day	8% 9% 5% 8% 5% 4 5% 5% 6% 7% 39%	1980
	21st to end	Day	11% 13% 5% 8% 7% 3 4 4 6% 6% 31%	2178
April	1st to 10th	Day	12% 12% 4 6% 6% 3 4 6% 6% 7% 34%	2049
	11th to 20th	Day	8% 9% 4 7% 6% 3 5% 5% 5% 7% 41%	2307
	21st to end	Day	9% 9% 4 6% 6% 3 4 5% 5% 7% 42%	2340
May	1st to 10th	Day	8% 8% 3 5% 6% 3 5% 5% 6% 8% 44%	2340
	11th to 20th	Day	7% 7% 3 6% 6% 4 5% 5% 5% 8% 44%	2305
	21st to end	Day	12% 7% 3 7% 6% 4 5% 5% 7% 8% 36%	2724
June	1st to 10th	Day	9% 4 2 5% 5% 3 5% 6% 7% 9% 46%	2644
	11th to 20th	Day	10% 5% 2 4 4 3 4 4 5% 8% 49%	2700
	21st to end	Day	2 2 1 2 3 2 3 4 5% 7% 68%	2700
July	1st to 10th	Day	2 2 1 3 3 3 3 4 5% 9% 66%	2700
	11th to 20th	Day	2 2 1 3 3 2 3 3 4 7% 70%	2532
	21st to end	Day	3 2 1 3 4 2 3 4 6% 7% 64%	2545
August	1st to 10th	Day	4 4 2 3 3 2 3 4 6% 7% 61%	2328
	11th to 20th	Day	3 2 1 2 2 2 3 3 4 8% 70%	2299
	21st to end	Day	4 3 1 3 3 3 4 4 5% 6% 65%	2574
September	1st to 10th	Day	5% 3 1 2 3 2 3 3 4 5% 69%	2102
	11th to 20th	Day	6% 3 2 4 3 3 3 4 5% 6% 61%	1980
	21st to end	Day	8% 4 2 3 3 2 2 3 5% 7% 62%	1980
October	1st to 10th	Day	12% 5% 2 4 4 3 4 5% 5% 5% 50%	1872
	11th to 20th	Day	10% 5% 2 4 5% 3 4 4 4 6% 53%	1800
	21st to end	Day	10% 6% 2 4 5% 3 4 5% 5% 6% 49%	1894
November	1st to 10th	Day	15% 9% 4 5% 5% 3 4 4 3 6% 41%	1674
	11th to 20th	Day	14% 9% 3 7% 6% 2 5% 4 6% 6% 39%	1558
	21st to end	Day	11% 14% 4 7% 5% 3 4 4 3 5% 40%	1520
December	1st to 10th	Day	14% 16% 6% 10% 7% 2 4 3 4 4 30%	1520
	11th to 20th	Day	17% 16% 6% 10% 8% 3 5% 4 4 4 24%	1827
	21st to end	Day	11% 12% 5% 8% 5% 3 4 6% 5% 7% 34%	2442
January	1st to 10th	Night	12% 17% 7% 12% 5% 3 4 4 4 6% 27%	4566
	11th to 20th	Night	19% 22% 6% 8% 6% 3 3 2 3 4 23%	4350
	21st to end	Night	19% 23% 7% 9% 5% 2 3 3 3 3 24%	4521
February	1st to 10th	Night	16% 17% 5% 9% 6% 3 3 4 4 6% 27%	2470
	11th to 20th	Night	15% 16% 5% 8% 5% 3 4 3 4 5% 31%	2402
	21st to end	Night	11% 15% 6% 12% 7% 3 5% 4 4 6% 27%	1830
March	1st to 10th	Night	10% 14% 4 6% 6% 3 6% 4 6% 7% 33%	2062
	11th to 20th	Night	10% 9% 4 7% 5% 3 4 4 5% 8% 41%	1980
	21st to end	Night	10% 13% 5% 8% 6% 3 5% 5% 5% 7% 32%	2178
April	1st to 10th	Night	11% 11% 4 7% 4 3 4 4 6% 7% 37%	1908
	11th to 20th	Night	11% 8% 3 7% 4 3 6% 6% 5% 8% 39%	1601
	21st to end	Night	10% 7% 2 5% 5% 3 5% 4 5% 7% 47%	1620
May	1st to 10th	Night	8% 7% 3 6% 4 4 5% 5% 5% 8% 45%	1620
	11th to 20th	Night	6% 6% 2 5% 5% 4 6% 6% 7% 9% 44%	1586
	21st to end	Night	12% 7% 3 6% 7% 3 5% 5% 6% 8% 39%	1552
June	1st to 10th	Night	9% 4 2 4 5% 3 5% 6% 7% 9% 47%	1312
	11th to 20th	Night	10% 4 2 4 3 3 5% 4 5% 8% 52%	1260
	21st to end	Night	2 2 1 2 3 2 4 3 5% 8% 67%	1260
July	1st to 10th	Night	2 2 1 2 3 2 4 4 7% 9% 65%	1260
	11th to 20th	Night	2 1 1 2 2 1 3 4 5% 7% 71%	1421
	21st to end	Night	2 2 1 3 3 3 4 4 4 8% 66%	1773
August	1st to 10th	Night	5% 3 2 4 5% 2 4 5% 5% 7% 58%	1611
	11th to 20th	Night	2 1 1 3 3 2 3 5% 4 8% 67%	1602
	21st to end	Night	4 3 1 3 3 2 3 4 4 7% 66%	1782
September	1st to 10th	Night	5% 3 2 3 3 2 3 4 4 5% 66%	1854
	11th to 20th	Night	6% 3 1 3 3 3 4 4 4 7% 62%	1980
	21st to end	Night	8% 4 1 3 3 2 2 3 4 6% 62%	1980
October	1st to 10th	Night	10% 6% 3 5% 4 3 3 3 4 5% 54%	2088
	11th to 20th	Night	12% 6% 2 3 4 2 3 3 4 5% 55%	2160
	21st to end	Night	9% 8% 3 5% 4 3 5% 4 5% 7% 47%	2461
November	1st to 10th	Night	15% 9% 3 5% 4 3 4 4 5% 6% 42%	2405
	11th to 20th	Night	14% 11% 4 5% 5% 3 5% 4 5% 7% 38%	2601
	21st to end	Night	11% 12% 5% 6% 5% 3 4 3 4 5% 41%	2660
December	1st to 10th	Night	14% 15% 6% 9% 7% 3 4 4 4 5% 31%	2660
	11th to 20th	Night	15% 18% 5% 9% 6% 3 4 4 4 5% 28%	3362
	21st to end	Night	13% 14% 5% 9% 6% 3 4 4 4 4 34%	5214

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% 13% 14% 3 1	2393
	11th to 20th	Day	61% 5% 14% 12% 7% 1	2608
	21st to end	Day	65% 5% 11% 12% 5% 1	3146
February	1st to 10th	Day	60% 7% 12% 17% 4	1710
	11th to 20th	Day	58% 5% 14% 17% 5% 1	1674
	21st to end	Day	53% 8% 14% 17% 7% 1	1516
March	1st to 10th	Day	49% 6% 17% 20% 7% 2	1898
	11th to 20th	Day	43% 7% 16% 23% 9% 1	1980
	21st to end	Day	54% 6% 14% 20% 6% 1	2178
April	1st to 10th	Day	47% 7% 15% 18% 12% 1	2049
	11th to 20th	Day	41% 5% 12% 26% 13% 2	2310
	21st to end	Day	41% 5% 11% 28% 14% 1	2340
May	1st to 10th	Day	37% 5% 9% 28% 18% 3	2340
	11th to 20th	Day	37% 6% 11% 30% 14% 2	2308
	21st to end	Day	44% 6% 13% 27% 9% 1	2724
June	1st to 10th	Day	34% 6% 14% 29% 17% 1	2644
	11th to 20th	Day	32% 5% 10% 22% 21% 10%	2700
	21st to end	Day	17% 3 6% 24% 32% 19%	2700
July	1st to 10th	Day	16% 4 4 18% 36% 23%	2626
	11th to 20th	Day	15% 3 4 17% 27% 35%	2455
	21st to end	Day	19% 3 5% 16% 28% 29%	2404
August	1st to 10th	Day	22% 3 7% 18% 27% 22%	2313
	11th to 20th	Day	14% 3 5% 19% 36% 23%	2299
	21st to end	Day	19% 3 5% 20% 32% 21%	2574
September	1st to 10th	Day	19% 3 7% 17% 32% 23%	2102
	11th to 20th	Day	24% 3 8% 25% 27% 13%	1980
	21st to end	Day	24% 3 8% 29% 27% 9%	1980
October	1st to 10th	Day	35% 4 11% 28% 16% 5%	1872
	11th to 20th	Day	33% 4 16% 31% 14% 2	1800
	21st to end	Day	35% 4 18% 24% 17% 1	1894
November	1st to 10th	Day	46% 4 18% 22% 10% 1	1674
	11th to 20th	Day	46% 6% 18% 21% 6% 3	1558
	21st to end	Day	47% 5% 19% 21% 8% 1	1520
December	1st to 10th	Day	58% 6% 12% 16% 6% 2	1520
	11th to 20th	Day	63% 5% 11% 18% 3	1825
	21st to end	Day	51% 6% 16% 20% 8%	2442
January	1st to 10th	Night	60% 5% 10% 21% 4	4566
	11th to 20th	Night	66% 5% 11% 12% 5% 1	4350
	21st to end	Night	67% 4 13% 11% 4 1	4521
February	1st to 10th	Night	59% 5% 15% 16% 5% 1	2470
	11th to 20th	Night	55% 4 15% 19% 6% 1	2403
	21st to end	Night	57% 6% 13% 16% 7% 1	1830
March	1st to 10th	Night	50% 6% 15% 21% 6% 1	2062
	11th to 20th	Night	41% 6% 16% 23% 11% 2	1980
	21st to end	Night	51% 6% 15% 21% 6% 1	2178
April	1st to 10th	Night	45% 6% 14% 21% 12% 3	1908
	11th to 20th	Night	42% 6% 12% 25% 13% 2	1601
	21st to end	Night	37% 5% 12% 28% 17%	1620
May	1st to 10th	Night	36% 5% 9% 29% 19% 1	1620
	11th to 20th	Night	33% 6% 13% 27% 18% 3	1587
	21st to end	Night	43% 5% 15% 24% 12% 2	1552
June	1st to 10th	Night	30% 8% 14% 24% 21% 2	1312
	11th to 20th	Night	31% 5% 7% 23% 24% 10%	1260
	21st to end	Night	15% 4 7% 21% 30% 22%	1260
July	1st to 10th	Night	15% 4 7% 18% 29% 27%	1225
	11th to 20th	Night	12% 3 4 15% 27% 39%	1375
	21st to end	Night	18% 4 5% 14% 25% 34%	1674
August	1st to 10th	Night	24% 4 7% 18% 21% 26%	1602
	11th to 20th	Night	17% 3 4 19% 33% 24%	1602
	21st to end	Night	19% 3 7% 17% 28% 27%	1782
September	1st to 10th	Night	20% 4 5% 14% 31% 26%	1854
	11th to 20th	Night	23% 4 8% 24% 24% 18%	1980
	21st to end	Night	24% 3 7% 23% 33% 10%	1980
October	1st to 10th	Night	32% 4 11% 26% 19% 7%	2088
	11th to 20th	Night	32% 3 12% 34% 16% 3	2160
	21st to end	Night	36% 5% 15% 24% 19% 1	2461
November	1st to 10th	Night	42% 5% 16% 25% 11% 2	2405
	11th to 20th	Night	46% 5% 16% 25% 6% 2	2601
	21st to end	Night	46% 4 19% 20% 10% 1	2660
December	1st to 10th	Night	57% 5% 17% 14% 7% 1	2660
	11th to 20th	Night	60% 5% 16% 17% 2	3363
	21st to end	Night	53% 5% 13% 18% 10% 1	5214

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% 9% 16% 21% 25% 6%	180
	11th to 20th	Day	23% 5% 14% 33% 19% 8%	200
	21st to end	Day	26% 5% 16% 31% 18% 3	297
February	1st to 10th	Day	23% 11% 28% 26% 11% 2	270
	11th to 20th	Day	20% 6% 29% 30% 13% 2	270
	21st to end	Day	16% 12% 28% 30% 11% 2	358
March	1st to 10th	Day	15% 15% 27% 32% 10% 1	420
	11th to 20th	Day	11% 11% 29% 30% 17% 2	420
	21st to end	Day	17% 16% 31% 27% 8% 1	462
April	1st to 10th	Day	20% 16% 24% 26% 12% 1	420
	11th to 20th	Day	15% 21% 30% 23% 11% 1	412
	21st to end	Day	15% 13% 25% 27% 15% 5%	420
May	1st to 10th	Day	13% 12% 26% 26% 18% 5%	423
	11th to 20th	Day	10% 11% 26% 28% 17% 7%	452
	21st to end	Day	15% 7% 21% 26% 22% 9%	679
June	1st to 10th	Day	9% 10% 21% 28% 24% 8%	630
	11th to 20th	Day	13% 13% 24% 29% 18% 3	630
	21st to end	Day	3 5% 21% 38% 27% 6%	630
July	1st to 10th	Day	4 4 23% 37% 26% 7%	621
	11th to 20th	Day	2 6% 24% 41% 23% 2	462
	21st to end	Day	3 5% 20% 34% 27% 11%	487
August	1st to 10th	Day	6% 4 22% 30% 32% 6%	447
	11th to 20th	Day	5% 5% 16% 27% 34% 13%	437
	21st to end	Day	6% 7% 20% 30% 24% 13%	495
September	1st to 10th	Day	5% 5% 23% 29% 28% 10%	450
	11th to 20th	Day	9% 7% 24% 27% 25% 8%	450
	21st to end	Day	10% 8% 19% 28% 26% 9%	450
October	1st to 10th	Day	11% 6% 18% 28% 28% 9%	342
	11th to 20th	Day	12% 10% 21% 22% 22% 13%	270
	21st to end	Day	17% 12% 20% 30% 18% 3	297
November	1st to 10th	Day	23% 9% 23% 25% 11% 8%	270
	11th to 20th	Day	14% 9% 22% 36% 16% 4	270
	21st to end	Day	18% 7% 21% 32% 20% 2	270
December	1st to 10th	Day	23% 6% 20% 30% 15% 6%	270
	11th to 20th	Day	34% 3 17% 28% 17% 1	241
	21st to end	Day	23% 9% 14% 28% 20% 7%	198
January	1st to 10th	Night	23% 4 15% 38% 18% 1	855
	11th to 20th	Night	25% 5% 18% 31% 18% 3	760
	21st to end	Night	23% 3 17% 41% 14% 2	836
February	1st to 10th	Night	25% 5% 21% 36% 12% 1	760
	11th to 20th	Night	21% 4 24% 38% 12% 2	744
	21st to end	Night	16% 7% 23% 39% 12% 3	610
March	1st to 10th	Night	17% 6% 21% 43% 12% 1	720
	11th to 20th	Night	15% 5% 24% 39% 16% 1	720
	21st to end	Night	16% 7% 25% 37% 14% 1	792
April	1st to 10th	Night	16% 7% 23% 40% 14% 1	666
	11th to 20th	Night	16% 7% 29% 36% 11% 1	533
	21st to end	Night	13% 5% 24% 39% 18% 1	540
May	1st to 10th	Night	9% 8% 26% 38% 18% 1	540
	11th to 20th	Night	9% 7% 23% 35% 24% 2	531
	21st to end	Night	14% 5% 23% 37% 20% 2	584
June	1st to 10th	Night	10% 5% 15% 42% 26% 3	412
	11th to 20th	Night	12% 3 26% 40% 18% 1	360
	21st to end	Night	3 2 14% 53% 27% 2	360
July	1st to 10th	Night	2 1 16% 48% 31% 2	350
	11th to 20th	Night	2 14% 63% 20%	354
	21st to end	Night	3 1 15% 48% 31% 2	591
August	1st to 10th	Night	5% 4 15% 47% 29% 1	537
	11th to 20th	Night	2 2 12% 50% 31% 3	534
	21st to end	Night	5% 2 17% 44% 28% 2	594
September	1st to 10th	Night	6% 2 16% 46% 26% 4	613
	11th to 20th	Night	7% 2 16% 39% 31% 5%	720
	21st to end	Night	11% 3 14% 39% 27% 6%	720
October	1st to 10th	Night	11% 4 17% 43% 23% 1	720
	11th to 20th	Night	13% 4 18% 39% 22% 3	720
	21st to end	Night	14% 6% 18% 43% 16% 4	792
November	1st to 10th	Night	18% 4 20% 38% 18% 1	740
	11th to 20th	Night	18% 5% 23% 39% 13% 1	891
	21st to end	Night	17% 5% 21% 37% 19% 2	950
December	1st to 10th	Night	21% 5% 20% 40% 12% 1	950
	11th to 20th	Night	24% 5% 17% 40% 13% 1	950
	21st to end	Night	27% 6% 19% 34% 13% 1	1045

Page generated at 2024-02-22 04:05:45. Version ac07

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