Hennepin Canal Parkway State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Hennepin Canal Parkway State Park clear sky chart from 2005-11-06 to 2024-01-14.

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	14% 8% 4 6% 6% 3 4 5% 5% 7% 38%	74783
	Night	14% 8% 4 6% 5% 3 4 4 5% 7% 40%	74993
Transparency	Day	45% 5% 12% 23% 13% 2	74484
	Night	44% 4 12% 23% 15% 2	74813
Seeing	Day	16% 10% 28% 26% 16% 5%	14631
	Night	17% 9% 31% 29% 12% 1	24607

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	12% 11% 6% 9% 8% 5% 5% 6% 5% 8% 25%	1517
	11th to 20th	Day	14% 16% 5% 12% 7% 4 4 4 5% 5% 22%	1464
	21st to end	Day	15% 16% 7% 10% 8% 3 5% 4 4 4 25%	1737
February	1st to 10th	Day	16% 12% 5% 11% 6% 3 6% 5% 4 6% 27%	1620
	11th to 20th	Day	14% 9% 4 8% 7% 4 5% 5% 4 6% 34%	1708
	21st to end	Day	15% 13% 6% 10% 6% 2 4 4 4 6% 30%	1480
March	1st to 10th	Day	16% 11% 6% 8% 5% 2 4 4 4 6% 34%	1800
	11th to 20th	Day	15% 8% 4 7% 6% 3 5% 4 5% 7% 36%	1934
	21st to end	Day	20% 10% 5% 8% 6% 4 5% 5% 5% 6% 25%	2330
April	1st to 10th	Day	14% 10% 5% 8% 6% 3 4 4 6% 6% 34%	2160
	11th to 20th	Day	17% 9% 4 5% 5% 3 4 4 5% 6% 37%	2134
	21st to end	Day	21% 8% 3 6% 6% 3 5% 4 4 6% 34%	2160
May	1st to 10th	Day	17% 7% 3 8% 5% 3 5% 6% 5% 9% 31%	2371
	11th to 20th	Day	20% 7% 3 6% 5% 3 5% 4 6% 7% 34%	2479
	21st to end	Day	14% 7% 3 6% 6% 4 5% 5% 6% 9% 35%	2725
June	1st to 10th	Day	10% 5% 2 4 5% 3 5% 5% 7% 9% 45%	2520
	11th to 20th	Day	8% 5% 2 5% 5% 3 5% 5% 6% 7% 47%	2520
	21st to end	Day	12% 5% 2 5% 6% 4 6% 5% 7% 9% 39%	2520
July	1st to 10th	Day	7% 5% 2 4 5% 3 4 5% 7% 9% 48%	2520
	11th to 20th	Day	9% 3 2 4 4 3 5% 5% 6% 10% 47%	2520
	21st to end	Day	7% 5% 2 5% 6% 3 5% 5% 7% 10% 45%	2743
August	1st to 10th	Day	7% 5% 2 5% 5% 4 5% 6% 8% 11% 42%	2387
	11th to 20th	Day	9% 5% 2 4 5% 3 4 5% 6% 9% 48%	2150
	21st to end	Day	10% 4 2 4 4 3 5% 5% 6% 8% 52%	2376
September	1st to 10th	Day	13% 5% 2 5% 5% 2 4 5% 6% 8% 45%	2160
	11th to 20th	Day	13% 4 2 3 3 2 3 4 5% 7% 55%	2111
	21st to end	Day	9% 4 2 6% 5% 3 5% 6% 5% 8% 48%	1980
October	1st to 10th	Day	13% 6% 2 4 5% 3 4 4 5% 6% 48%	1832
	11th to 20th	Day	17% 8% 4 6% 5% 3 4 3 6% 5% 40%	1800
	21st to end	Day	20% 9% 3 5% 4 2 4 4 4 6% 39%	1859
November	1st to 10th	Day	11% 7% 2 6% 4 3 4 4 6% 6% 47%	1672
	11th to 20th	Day	16% 10% 4 7% 5% 4 4 4 5% 7% 35%	1710
	21st to end	Day	17% 11% 4 7% 5% 2 5% 3 3 6% 37%	1563
December	1st to 10th	Day	14% 12% 5% 7% 7% 3 4 4 3 5% 35%	1520
	11th to 20th	Day	13% 13% 4 10% 7% 5% 5% 4 6% 5% 29%	1918
	21st to end	Day	24% 18% 9% 10% 7% 2 2 3 3 4 16%	2783
January	1st to 10th	Night	13% 11% 5% 10% 5% 3 5% 3 4 6% 35%	2648
	11th to 20th	Night	14% 13% 7% 9% 6% 4 4 4 4 6% 29%	2569
	21st to end	Night	14% 12% 6% 10% 6% 4 5% 5% 4 6% 29%	2614
February	1st to 10th	Night	16% 12% 5% 8% 6% 3 4 4 5% 5% 32%	2340
	11th to 20th	Night	13% 9% 4 8% 5% 3 4 5% 5% 6% 38%	2138
	21st to end	Night	17% 10% 5% 9% 6% 2 4 3 3 5% 37%	1776
March	1st to 10th	Night	16% 9% 4 6% 5% 4 5% 4 4 6% 37%	2160
	11th to 20th	Night	15% 8% 4 6% 5% 3 5% 4 5% 7% 39%	2039
	21st to end	Night	21% 9% 5% 7% 6% 3 4 4 5% 6% 30%	2026
April	1st to 10th	Night	16% 10% 3 6% 5% 2 4 3 5% 6% 39%	1800
	11th to 20th	Night	18% 8% 3 6% 5% 2 4 4 4 5% 41%	1775
	21st to end	Night	16% 8% 3 7% 6% 3 4 4 4 8% 35%	1798
May	1st to 10th	Night	15% 7% 3 5% 6% 3 6% 6% 6% 8% 35%	1585
	11th to 20th	Night	17% 6% 2 4 6% 3 4 4 6% 8% 40%	1416
	21st to end	Night	12% 6% 2 5% 6% 3 4 5% 6% 9% 41%	1551
June	1st to 10th	Night	9% 5% 2 5% 4 3 5% 5% 5% 7% 51%	1440
	11th to 20th	Night	9% 3 3 5% 4 4 6% 5% 6% 9% 48%	1440
	21st to end	Night	10% 4 2 4 5% 4 6% 5% 6% 8% 47%	1440
July	1st to 10th	Night	8% 4 2 4 3 3 4 5% 7% 10% 51%	1440
	11th to 20th	Night	6% 3 2 3 3 3 4 4 6% 9% 56%	1440
	21st to end	Night	5% 3 2 4 5% 2 5% 6% 7% 9% 52%	1575
August	1st to 10th	Night	5% 4 2 4 5% 3 4 5% 6% 8% 53%	1548
	11th to 20th	Night	7% 4 2 4 4 2 4 4 6% 8% 54%	1750
	21st to end	Night	8% 3 2 4 4 2 4 4 4 7% 58%	1980
September	1st to 10th	Night	12% 5% 1 4 4 2 3 4 4 6% 55%	1800
	11th to 20th	Night	10% 3 2 3 5% 2 4 4 5% 7% 54%	1831
	21st to end	Night	8% 4 3 4 5% 3 4 6% 6% 7% 49%	1980
October	1st to 10th	Night	10% 5% 2 5% 4 3 4 3 4 5% 54%	2126
	11th to 20th	Night	16% 6% 3 5% 4 2 3 4 5% 6% 46%	2160
	21st to end	Night	19% 9% 3 5% 5% 3 3 4 4 5% 39%	2497
November	1st to 10th	Night	10% 7% 3 4 4 2 3 3 5% 7% 52%	2406
	11th to 20th	Night	14% 9% 3 6% 5% 3 4 5% 5% 7% 40%	2470
	21st to end	Night	17% 9% 4 6% 5% 3 4 4 4 6% 39%	2612
December	1st to 10th	Night	15% 11% 4 7% 6% 3 5% 4 5% 6% 35%	2660
	11th to 20th	Night	15% 11% 6% 8% 5% 3 4 3 4 6% 34%	3279
	21st to end	Night	23% 15% 7% 9% 7% 4 5% 4 4 4 18%	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	56% 5% 13% 15% 10% 1	1518
	11th to 20th	Day	64% 5% 11% 15% 5%	1464
	21st to end	Day	63% 4 10% 13% 9% 1	1737
February	1st to 10th	Day	60% 4 13% 16% 6% 2	1620
	11th to 20th	Day	51% 4 12% 22% 9% 1	1718
	21st to end	Day	56% 4 12% 19% 9% 1	1480
March	1st to 10th	Day	51% 4 14% 21% 9% 1	1800
	11th to 20th	Day	49% 4 14% 23% 9% 1	1934
	21st to end	Day	59% 6% 10% 20% 4 1	2330
April	1st to 10th	Day	50% 4 12% 23% 11% 1	2160
	11th to 20th	Day	48% 4 9% 24% 12% 2	2134
	21st to end	Day	51% 5% 10% 20% 12% 2	2160
May	1st to 10th	Day	50% 5% 14% 21% 9%	2371
	11th to 20th	Day	49% 6% 10% 22% 12%	2483
	21st to end	Day	45% 7% 13% 18% 15% 2	2725
June	1st to 10th	Day	34% 6% 14% 28% 16% 2	2520
	11th to 20th	Day	35% 7% 11% 23% 22% 3	2520
	21st to end	Day	41% 6% 13% 24% 14% 2	2520
July	1st to 10th	Day	32% 6% 15% 28% 16% 3	2451
	11th to 20th	Day	32% 7% 15% 30% 14% 3	2445
	21st to end	Day	33% 6% 16% 27% 16% 2	2591
August	1st to 10th	Day	35% 9% 15% 29% 12% 1	2372
	11th to 20th	Day	33% 6% 15% 26% 18% 2	2150
	21st to end	Day	30% 6% 11% 29% 20% 3	2376
September	1st to 10th	Day	37% 6% 11% 24% 18% 4	2160
	11th to 20th	Day	30% 4 11% 30% 22% 3	2111
	21st to end	Day	34% 6% 9% 28% 21% 2	1980
October	1st to 10th	Day	38% 5% 10% 27% 20% 1	1832
	11th to 20th	Day	46% 3 9% 24% 16% 2	1800
	21st to end	Day	48% 4 12% 23% 10% 3	1859
November	1st to 10th	Day	37% 3 15% 25% 16% 3	1672
	11th to 20th	Day	50% 3 12% 23% 11% 1	1710
	21st to end	Day	50% 5% 12% 23% 8%	1563
December	1st to 10th	Day	53% 4 13% 20% 9% 1	1520
	11th to 20th	Day	56% 4 13% 20% 8% 1	1915
	21st to end	Day	74% 3 9% 9% 5%	2783
January	1st to 10th	Night	52% 4 11% 20% 13% 1	2648
	11th to 20th	Night	58% 4 14% 15% 9%	2569
	21st to end	Night	56% 4 13% 17% 10% 1	2614
February	1st to 10th	Night	55% 4 11% 18% 11% 1	2340
	11th to 20th	Night	47% 4 12% 23% 13% 1	2139
	21st to end	Night	52% 2 10% 21% 12% 3	1776
March	1st to 10th	Night	49% 4 12% 23% 11% 1	2160
	11th to 20th	Night	45% 4 12% 21% 13% 4	2039
	21st to end	Night	56% 4 11% 19% 10% 1	2026
April	1st to 10th	Night	46% 4 11% 23% 13% 2	1800
	11th to 20th	Night	46% 4 7% 24% 15% 4	1775
	21st to end	Night	48% 4 11% 22% 11% 3	1798
May	1st to 10th	Night	45% 6% 13% 23% 12% 1	1585
	11th to 20th	Night	42% 6% 12% 25% 15% 1	1417
	21st to end	Night	39% 7% 13% 21% 17% 2	1552
June	1st to 10th	Night	32% 5% 14% 25% 20% 3	1440
	11th to 20th	Night	33% 5% 11% 23% 23% 5%	1440
	21st to end	Night	34% 8% 14% 21% 20% 3	1440
July	1st to 10th	Night	29% 6% 14% 31% 16% 4	1400
	11th to 20th	Night	26% 5% 13% 31% 21% 3	1392
	21st to end	Night	26% 6% 16% 28% 19% 5%	1487
August	1st to 10th	Night	28% 5% 17% 32% 15% 3	1539
	11th to 20th	Night	28% 6% 12% 32% 20% 2	1750
	21st to end	Night	27% 4 11% 29% 23% 5%	1980
September	1st to 10th	Night	30% 4 10% 27% 25% 4	1800
	11th to 20th	Night	30% 4 10% 31% 22% 4	1831
	21st to end	Night	31% 6% 11% 28% 21% 3	1980
October	1st to 10th	Night	34% 4 11% 25% 24% 3	2126
	11th to 20th	Night	40% 3 9% 25% 20% 3	2160
	21st to end	Night	47% 4 10% 23% 14% 2	2497
November	1st to 10th	Night	33% 4 13% 27% 19% 4	2406
	11th to 20th	Night	44% 4 12% 24% 14% 2	2470
	21st to end	Night	48% 3 11% 25% 13% 1	2612
December	1st to 10th	Night	51% 3 13% 22% 9% 1	2660
	11th to 20th	Night	52% 3 12% 23% 9% 1	3281
	21st to end	Night	70% 3 9% 12% 5%	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	20% 14% 36% 23% 7% 1	270
	11th to 20th	Day	24% 15% 37% 19% 4 1	249
	21st to end	Day	17% 19% 36% 20% 7% 1	264
February	1st to 10th	Day	22% 15% 42% 18% 3	240
	11th to 20th	Day	23% 17% 36% 16% 6% 1	240
	21st to end	Day	23% 17% 43% 16% 2	198
March	1st to 10th	Day	20% 21% 36% 18% 5%	240
	11th to 20th	Day	24% 16% 35% 16% 8% 1	240
	21st to end	Day	29% 13% 33% 18% 7% 1	416
April	1st to 10th	Day	22% 14% 32% 26% 5% 1	420
	11th to 20th	Day	21% 17% 30% 18% 12% 2	412
	21st to end	Day	26% 11% 32% 22% 8% 2	420
May	1st to 10th	Day	19% 13% 32% 27% 8% 2	454
	11th to 20th	Day	23% 10% 26% 24% 14% 3	625
	21st to end	Day	15% 8% 27% 27% 15% 9%	679
June	1st to 10th	Day	10% 6% 27% 30% 21% 7%	630
	11th to 20th	Day	10% 3 29% 31% 22% 4	630
	21st to end	Day	12% 7% 28% 31% 16% 6%	630
July	1st to 10th	Day	10% 3 15% 29% 26% 17%	621
	11th to 20th	Day	10% 4 21% 31% 25% 9%	618
	21st to end	Day	7% 3 21% 34% 28% 8%	684
August	1st to 10th	Day	8% 3 19% 34% 26% 10%	626
	11th to 20th	Day	11% 4 17% 28% 26% 14%	464
	21st to end	Day	7% 4 15% 36% 27% 11%	495
September	1st to 10th	Day	15% 6% 17% 30% 25% 7%	450
	11th to 20th	Day	11% 3 17% 31% 28% 11%	450
	21st to end	Day	9% 9% 28% 26% 22% 5%	450
October	1st to 10th	Day	17% 9% 25% 28% 17% 4	302
	11th to 20th	Day	19% 23% 33% 17% 6%	270
	21st to end	Day	32% 14% 28% 23% 3 1	297
November	1st to 10th	Day	14% 13% 39% 21% 9% 4	270
	11th to 20th	Day	20% 20% 30% 20% 8% 2	270
	21st to end	Day	26% 11% 33% 24% 6%	270
December	1st to 10th	Day	16% 17% 39% 20% 5% 3	270
	11th to 20th	Day	16% 13% 37% 28% 6%	270
	21st to end	Day	24% 19% 39% 15% 3	297
January	1st to 10th	Night	17% 14% 39% 23% 5%	950
	11th to 20th	Night	20% 13% 40% 21% 6% 1	918
	21st to end	Night	19% 14% 37% 25% 5%	990
February	1st to 10th	Night	24% 12% 38% 23% 4	900
	11th to 20th	Night	18% 13% 38% 26% 4	743
	21st to end	Night	23% 13% 40% 20% 3 1	592
March	1st to 10th	Night	20% 13% 38% 23% 5% 1	720
	11th to 20th	Night	20% 9% 32% 30% 8% 1	599
	21st to end	Night	23% 12% 36% 21% 6% 1	594
April	1st to 10th	Night	21% 12% 38% 24% 5%	540
	11th to 20th	Night	23% 12% 30% 29% 6%	533
	21st to end	Night	18% 13% 33% 29% 7%	540
May	1st to 10th	Night	19% 8% 35% 28% 9% 1	540
	11th to 20th	Night	20% 6% 28% 36% 10% 1	531
	21st to end	Night	13% 5% 28% 34% 18% 1	584
June	1st to 10th	Night	11% 4 23% 47% 15% 1	540
	11th to 20th	Night	9% 4 29% 41% 16%	540
	21st to end	Night	11% 5% 27% 41% 16% 1	540
July	1st to 10th	Night	8% 2 12% 40% 32% 5%	525
	11th to 20th	Night	7% 1 19% 45% 24% 4	522
	21st to end	Night	5% 2 16% 46% 30% 1	591
August	1st to 10th	Night	6% 2 16% 41% 31% 4	537
	11th to 20th	Night	7% 3 13% 39% 33% 5%	534
	21st to end	Night	10% 1 15% 42% 31% 2	594
September	1st to 10th	Night	14% 5% 16% 37% 26% 3	540
	11th to 20th	Night	12% 3 18% 35% 28% 4	571
	21st to end	Night	10% 8% 25% 34% 21% 2	720
October	1st to 10th	Night	13% 6% 31% 31% 18% 2	720
	11th to 20th	Night	18% 13% 31% 26% 11%	720
	21st to end	Night	25% 11% 33% 23% 7%	792
November	1st to 10th	Night	15% 12% 38% 25% 9% 1	740
	11th to 20th	Night	18% 14% 38% 24% 6%	760
	21st to end	Night	21% 12% 35% 25% 6%	902
December	1st to 10th	Night	22% 12% 37% 22% 6%	950
	11th to 20th	Night	22% 11% 35% 25% 6%	950
	21st to end	Night	28% 15% 33% 21% 3	1045

Page generated at 2024-01-11 03:22:42. Version ac07

Copyright 2024 Attilla Danko