Weber County North Fork Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Weber County North Fork 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% 10% 4 6% 5% 3 4 4 5% 6% 46%	78900
	Night	9% 10% 4 6% 5% 3 4 4 5% 6% 45%	80432
Transparency	Day	37% 6% 11% 18% 18% 10%	78623
	Night	40% 5% 11% 20% 16% 8%	80230
Seeing	Day	14% 13% 30% 28% 12% 3	14202
	Night	14% 6% 18% 37% 22% 3	24303

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	9% 21% 7% 10% 6% 3 4 4 3 5% 29%	2858
	11th to 20th	Day	9% 22% 9% 11% 6% 3 3 3 3 4 28%	2860
	21st to end	Day	8% 20% 8% 9% 5% 2 3 3 3 5% 32%	3146
February	1st to 10th	Day	14% 18% 5% 8% 6% 3 3 4 4 6% 29%	1710
	11th to 20th	Day	10% 19% 6% 9% 6% 2 5% 3 4 5% 31%	1721
	21st to end	Day	7% 19% 9% 12% 5% 3 4 4 4 5% 27%	1521
March	1st to 10th	Day	11% 16% 7% 7% 6% 2 5% 4 4 7% 33%	1914
	11th to 20th	Day	8% 14% 4 7% 6% 3 5% 6% 7% 7% 34%	1980
	21st to end	Day	14% 17% 4 8% 6% 3 5% 4 5% 6% 28%	2178
April	1st to 10th	Day	14% 12% 4 7% 6% 2 4 4 5% 6% 36%	2002
	11th to 20th	Day	11% 13% 4 7% 5% 3 4 4 4 5% 38%	2288
	21st to end	Day	11% 12% 3 5% 5% 2 4 3 5% 7% 42%	2340
May	1st to 10th	Day	10% 10% 3 7% 6% 3 4 6% 5% 8% 38%	2340
	11th to 20th	Day	9% 7% 3 5% 5% 3 5% 6% 5% 10% 41%	2301
	21st to end	Day	13% 6% 3 6% 6% 4 6% 5% 6% 7% 38%	2530
June	1st to 10th	Day	7% 4 2 4 4 3 4 5% 5% 7% 55%	2506
	11th to 20th	Day	8% 4 2 4 4 2 3 3 4 7% 57%	2548
	21st to end	Day	4 2 1 3 3 2 3 3 3 4 71%	2640
July	1st to 10th	Day	4 2 1 3 3 2 3 4 5% 7% 65%	2453
	11th to 20th	Day	4 4 1 3 3 2 3 4 4 6% 66%	2340
	21st to end	Day	5% 2 2 3 4 3 4 4 6% 7% 60%	2545
August	1st to 10th	Day	5% 3 1 3 4 3 4 4 5% 7% 61%	2328
	11th to 20th	Day	4 2 1 3 3 2 3 4 5% 5% 67%	2299
	21st to end	Day	4 3 1 3 3 2 3 4 4 6% 66%	2569
September	1st to 10th	Day	4 3 1 2 2 2 3 4 4 5% 69%	2039
	11th to 20th	Day	6% 3 1 4 4 2 4 3 4 5% 64%	1980
	21st to end	Day	8% 4 1 2 3 2 3 3 4 4 66%	1980
October	1st to 10th	Day	13% 6% 2 5% 4 2 3 4 4 4 52%	1890
	11th to 20th	Day	9% 6% 2 5% 4 2 3 4 5% 5% 55%	1800
	21st to end	Day	7% 8% 3 4 4 2 3 4 4 6% 54%	1949
November	1st to 10th	Day	12% 12% 3 7% 4 3 3 4 4 6% 42%	1674
	11th to 20th	Day	15% 10% 3 3 5% 2 3 4 5% 7% 43%	1710
	21st to end	Day	10% 13% 6% 7% 4 3 4 3 5% 6% 40%	1525
December	1st to 10th	Day	11% 13% 5% 8% 7% 3 3 4 3 5% 36%	1520
	11th to 20th	Day	13% 14% 7% 9% 6% 3 5% 4 5% 7% 28%	1926
	21st to end	Day	8% 13% 6% 9% 6% 3 5% 5% 6% 6% 34%	2990
January	1st to 10th	Night	8% 16% 7% 12% 6% 3 3 3 4 6% 32%	4097
	11th to 20th	Night	10% 23% 6% 11% 6% 2 4 4 4 5% 26%	4110
	21st to end	Night	9% 21% 6% 8% 5% 2 3 4 4 5% 33%	4521
February	1st to 10th	Night	12% 17% 5% 8% 6% 3 4 4 4 5% 32%	2470
	11th to 20th	Night	11% 13% 4 8% 6% 2 4 3 4 5% 40%	2345
	21st to end	Night	7% 16% 6% 11% 6% 3 4 4 4 6% 33%	1829
March	1st to 10th	Night	12% 15% 5% 6% 5% 3 5% 5% 4 5% 34%	2044
	11th to 20th	Night	9% 11% 3 7% 5% 3 4 4 6% 7% 41%	1980
	21st to end	Night	12% 14% 4 7% 5% 3 4 4 5% 6% 37%	2178
April	1st to 10th	Night	13% 13% 3 6% 5% 2 3 3 4 5% 42%	1958
	11th to 20th	Night	10% 10% 5% 7% 5% 3 4 4 4 6% 43%	1618
	21st to end	Night	11% 9% 3 5% 4 3 3 4 5% 5% 48%	1620
May	1st to 10th	Night	13% 8% 3 5% 5% 3 5% 5% 4 6% 43%	1620
	11th to 20th	Night	11% 4 3 5% 5% 3 4 4 6% 7% 48%	1594
	21st to end	Night	13% 6% 3 5% 6% 3 5% 4 6% 7% 42%	1746
June	1st to 10th	Night	7% 3 2 3 5% 3 4 4 6% 7% 55%	1450
	11th to 20th	Night	8% 3 1 4 3 2 2 4 4 6% 62%	1402
	21st to end	Night	4 2 1 2 3 2 2 3 3 7% 70%	1313
July	1st to 10th	Night	5% 4 1 4 4 2 4 4 6% 7% 60%	1500
	11th to 20th	Night	5% 4 2 4 4 2 4 5% 5% 6% 60%	1620
	21st to end	Night	4 3 1 5% 4 2 4 5% 6% 9% 56%	1773
August	1st to 10th	Night	5% 3 2 4 5% 3 4 5% 6% 6% 58%	1611
	11th to 20th	Night	3 3 2 4 4 2 4 4 6% 7% 61%	1602
	21st to end	Night	5% 3 1 3 4 3 4 4 5% 6% 62%	1786
September	1st to 10th	Night	5% 2 1 4 4 2 3 4 4 4 68%	1916
	11th to 20th	Night	7% 3 2 2 2 2 3 3 4 5% 66%	1980
	21st to end	Night	8% 3 1 3 3 2 2 3 3 5% 68%	1980
October	1st to 10th	Night	10% 5% 2 4 4 2 4 4 4 5% 57%	2068
	11th to 20th	Night	11% 6% 2 3 4 2 3 3 4 5% 58%	2160
	21st to end	Night	8% 6% 2 4 4 2 3 4 4 6% 56%	2402
November	1st to 10th	Night	12% 9% 2 5% 4 2 4 3 5% 6% 47%	2405
	11th to 20th	Night	11% 8% 3 5% 5% 2 4 4 5% 7% 45%	2470
	21st to end	Night	8% 11% 4 6% 6% 3 5% 3 4 5% 45%	2631
December	1st to 10th	Night	11% 12% 5% 8% 6% 3 3 4 4 5% 38%	2660
	11th to 20th	Night	13% 13% 5% 8% 6% 4 4 5% 5% 6% 32%	3271
	21st to end	Night	9% 13% 6% 9% 6% 3 4 4 5% 6% 35%	4702

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	57% 7% 13% 18% 4 1	2859
	11th to 20th	Day	62% 6% 14% 13% 4 1	2860
	21st to end	Day	54% 8% 15% 16% 6% 1	3146
February	1st to 10th	Day	56% 6% 15% 14% 8% 1	1710
	11th to 20th	Day	54% 6% 13% 16% 9% 1	1730
	21st to end	Day	58% 6% 10% 16% 8% 1	1521
March	1st to 10th	Day	51% 6% 12% 22% 8% 1	1914
	11th to 20th	Day	45% 8% 13% 21% 11% 2	1980
	21st to end	Day	55% 7% 13% 17% 7% 2	2178
April	1st to 10th	Day	48% 6% 12% 18% 13% 4	2002
	11th to 20th	Day	46% 7% 9% 21% 16% 1	2291
	21st to end	Day	41% 5% 10% 23% 19% 1	2340
May	1st to 10th	Day	41% 7% 11% 21% 19% 2	2340
	11th to 20th	Day	36% 7% 9% 25% 19% 5%	2304
	21st to end	Day	40% 9% 10% 23% 15% 2	2530
June	1st to 10th	Day	26% 6% 11% 23% 29% 6%	2506
	11th to 20th	Day	26% 4 8% 18% 26% 18%	2548
	21st to end	Day	16% 2 5% 12% 31% 33%	2640
July	1st to 10th	Day	17% 4 6% 15% 24% 34%	2387
	11th to 20th	Day	18% 4 6% 11% 26% 35%	2271
	21st to end	Day	20% 4 8% 12% 28% 27%	2404
August	1st to 10th	Day	21% 4 7% 16% 24% 28%	2313
	11th to 20th	Day	17% 4 7% 13% 35% 25%	2299
	21st to end	Day	18% 4 6% 15% 33% 24%	2569
September	1st to 10th	Day	17% 3 7% 16% 29% 29%	2039
	11th to 20th	Day	21% 5% 8% 16% 32% 18%	1980
	21st to end	Day	21% 4 7% 21% 36% 11%	1980
October	1st to 10th	Day	34% 5% 8% 22% 23% 7%	1890
	11th to 20th	Day	29% 5% 11% 28% 23% 4	1800
	21st to end	Day	31% 5% 14% 29% 19% 2	1949
November	1st to 10th	Day	43% 6% 12% 20% 17% 1	1674
	11th to 20th	Day	40% 5% 16% 25% 14%	1710
	21st to end	Day	45% 5% 14% 22% 14% 1	1525
December	1st to 10th	Day	51% 7% 17% 15% 9% 2	1520
	11th to 20th	Day	55% 6% 14% 19% 5%	1924
	21st to end	Day	49% 6% 14% 19% 12% 1	2990
January	1st to 10th	Night	55% 6% 11% 21% 6% 1	4097
	11th to 20th	Night	62% 6% 14% 12% 5% 1	4110
	21st to end	Night	53% 8% 16% 17% 5% 2	4521
February	1st to 10th	Night	53% 7% 14% 19% 7%	2470
	11th to 20th	Night	47% 5% 11% 21% 15% 2	2346
	21st to end	Night	51% 6% 11% 21% 10% 2	1829
March	1st to 10th	Night	51% 5% 11% 23% 10%	2044
	11th to 20th	Night	40% 7% 13% 23% 15% 2	1980
	21st to end	Night	47% 5% 14% 23% 9% 2	2178
April	1st to 10th	Night	44% 5% 12% 20% 13% 6%	1958
	11th to 20th	Night	41% 5% 10% 22% 19% 2	1618
	21st to end	Night	36% 4 11% 25% 21% 2	1620
May	1st to 10th	Night	40% 5% 11% 20% 21% 3	1620
	11th to 20th	Night	33% 7% 9% 26% 20% 6%	1595
	21st to end	Night	39% 6% 13% 23% 18% 2	1746
June	1st to 10th	Night	25% 6% 11% 21% 30% 6%	1450
	11th to 20th	Night	22% 3 7% 21% 29% 18%	1402
	21st to end	Night	16% 2 4 13% 30% 34%	1313
July	1st to 10th	Night	22% 3 9% 12% 23% 31%	1457
	11th to 20th	Night	24% 4 6% 13% 25% 30%	1566
	21st to end	Night	21% 5% 9% 14% 24% 28%	1674
August	1st to 10th	Night	24% 4 8% 15% 22% 27%	1602
	11th to 20th	Night	22% 3 8% 13% 27% 28%	1602
	21st to end	Night	22% 4 7% 11% 29% 27%	1786
September	1st to 10th	Night	20% 3 6% 14% 23% 34%	1916
	11th to 20th	Night	21% 3 6% 15% 31% 23%	1980
	21st to end	Night	21% 3 6% 18% 36% 17%	1980
October	1st to 10th	Night	29% 4 9% 23% 27% 8%	2068
	11th to 20th	Night	29% 3 7% 30% 25% 6%	2160
	21st to end	Night	27% 5% 11% 31% 21% 4	2402
November	1st to 10th	Night	37% 5% 11% 24% 20% 4	2405
	11th to 20th	Night	37% 5% 14% 26% 16% 2	2470
	21st to end	Night	42% 4 12% 26% 13% 3	2631
December	1st to 10th	Night	47% 5% 16% 19% 9% 3	2660
	11th to 20th	Night	51% 7% 14% 20% 7%	3272
	21st to end	Night	50% 5% 16% 17% 12% 1	4702

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	27% 12% 24% 23% 12% 2	270
	11th to 20th	Day	18% 13% 31% 26% 11% 1	270
	21st to end	Day	15% 14% 26% 35% 7% 2	297
February	1st to 10th	Day	27% 15% 33% 20% 4 1	270
	11th to 20th	Day	20% 15% 39% 19% 6% 1	326
	21st to end	Day	17% 20% 39% 19% 4 1	363
March	1st to 10th	Day	21% 20% 31% 23% 5%	420
	11th to 20th	Day	16% 17% 35% 24% 7% 1	420
	21st to end	Day	29% 16% 35% 17% 3	462
April	1st to 10th	Day	21% 19% 32% 19% 9%	420
	11th to 20th	Day	22% 25% 30% 17% 5% 2	412
	21st to end	Day	20% 20% 27% 21% 9% 2	420
May	1st to 10th	Day	18% 18% 32% 22% 9%	423
	11th to 20th	Day	17% 15% 28% 27% 11% 2	448
	21st to end	Day	15% 13% 30% 25% 15% 3	485
June	1st to 10th	Day	6% 13% 25% 34% 18% 4	616
	11th to 20th	Day	11% 12% 30% 29% 15% 2	630
	21st to end	Day	6% 8% 33% 31% 19% 4	570
July	1st to 10th	Day	4 8% 36% 37% 13% 3	446
	11th to 20th	Day	4 7% 37% 36% 12% 4	444
	21st to end	Day	5% 2 31% 41% 15% 5%	487
August	1st to 10th	Day	9% 5% 32% 35% 15% 5%	447
	11th to 20th	Day	5% 5% 27% 42% 16% 5%	437
	21st to end	Day	5% 6% 27% 39% 17% 5%	495
September	1st to 10th	Day	4 11% 28% 34% 17% 6%	450
	11th to 20th	Day	8% 10% 28% 34% 15% 6%	450
	21st to end	Day	10% 12% 28% 30% 18% 2	450
October	1st to 10th	Day	15% 13% 25% 27% 17% 4	360
	11th to 20th	Day	10% 14% 26% 23% 23% 4	270
	21st to end	Day	14% 12% 32% 30% 10% 1	297
November	1st to 10th	Day	24% 14% 20% 26% 11% 5%	270
	11th to 20th	Day	15% 13% 29% 30% 10% 3	270
	21st to end	Day	15% 12% 21% 30% 19% 3	270
December	1st to 10th	Day	16% 11% 31% 25% 13% 5%	270
	11th to 20th	Day	21% 10% 30% 30% 7% 3	270
	21st to end	Day	26% 13% 27% 23% 8% 3	297
January	1st to 10th	Night	20% 6% 17% 35% 19% 3	760
	11th to 20th	Night	20% 6% 19% 36% 16% 3	760
	21st to end	Night	19% 6% 19% 36% 15% 4	836
February	1st to 10th	Night	21% 7% 24% 35% 11% 2	760
	11th to 20th	Night	15% 7% 27% 36% 14% 2	744
	21st to end	Night	12% 9% 30% 34% 14% 1	610
March	1st to 10th	Night	20% 8% 21% 37% 11% 3	720
	11th to 20th	Night	14% 6% 21% 40% 16% 3	720
	21st to end	Night	21% 9% 19% 35% 14% 2	792
April	1st to 10th	Night	21% 8% 22% 33% 14% 1	698
	11th to 20th	Night	16% 12% 23% 34% 14% 2	533
	21st to end	Night	17% 5% 19% 37% 19% 3	540
May	1st to 10th	Night	16% 6% 24% 33% 19% 1	540
	11th to 20th	Night	14% 5% 16% 32% 29% 4	531
	21st to end	Night	14% 6% 16% 35% 25% 4	584
June	1st to 10th	Night	9% 6% 16% 37% 30% 2	540
	11th to 20th	Night	10% 6% 22% 38% 23% 2	502
	21st to end	Night	6% 3 18% 37% 31% 6%	360
July	1st to 10th	Night	7% 4 14% 35% 36% 4	407
	11th to 20th	Night	7% 3 12% 44% 32% 2	522
	21st to end	Night	5% 1 6% 43% 42% 4	591
August	1st to 10th	Night	7% 2 11% 44% 35% 1	537
	11th to 20th	Night	3 1 11% 43% 38% 3	534
	21st to end	Night	7% 3 11% 40% 35% 4	594
September	1st to 10th	Night	6% 5% 11% 40% 34% 4	656
	11th to 20th	Night	8% 5% 12% 38% 29% 8%	720
	21st to end	Night	9% 5% 16% 32% 29% 9%	720
October	1st to 10th	Night	13% 6% 14% 38% 25% 4	720
	11th to 20th	Night	15% 4 15% 34% 28% 4	720
	21st to end	Night	12% 5% 18% 35% 26% 4	792
November	1st to 10th	Night	16% 6% 14% 38% 22% 4	740
	11th to 20th	Night	16% 4 20% 40% 16% 4	760
	21st to end	Night	14% 8% 20% 34% 20% 4	921
December	1st to 10th	Night	17% 7% 24% 37% 14% 1	950
	11th to 20th	Night	21% 8% 23% 34% 12% 2	950
	21st to end	Night	24% 8% 24% 32% 9% 2	939

Page generated at 2024-02-22 04:05:47. Version ac07

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