Terre Haute
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Terre Haute clear sky chart from 2005-11-06 to 2024-01-27.

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	15% 7% 3 6% 5% 3 4 5% 5% 7% 39%	74943
	Night	15% 8% 3 6% 5% 3 4 4 5% 7% 41%	75117
Transparency	Day	44% 6% 12% 23% 14% 2	74645
	Night	44% 5% 11% 22% 15% 3	74936
Seeing	Day	16% 9% 25% 25% 18% 7%	14486
	Night	18% 8% 27% 31% 15% 1	24455

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% 13% 5% 9% 6% 3 3 4 4 5% 30%	1517
	11th to 20th	Day	19% 13% 5% 10% 6% 4 4 4 4 5% 27%	1520
	21st to end	Day	17% 13% 7% 8% 5% 3 3 3 5% 5% 30%	1719
February	1st to 10th	Day	19% 11% 6% 8% 6% 2 3 4 5% 5% 30%	1784
	11th to 20th	Day	17% 9% 5% 10% 6% 4 4 4 5% 6% 31%	1748
	21st to end	Day	18% 12% 4 7% 6% 3 4 4 3 5% 33%	1480
March	1st to 10th	Day	17% 10% 3 7% 5% 2 4 3 5% 5% 38%	1800
	11th to 20th	Day	18% 10% 4 6% 5% 3 5% 4 4 6% 35%	1854
	21st to end	Day	22% 11% 4 7% 5% 3 4 4 5% 6% 28%	2359
April	1st to 10th	Day	17% 9% 3 5% 5% 3 4 4 5% 7% 39%	2160
	11th to 20th	Day	18% 7% 2 5% 5% 3 4 5% 5% 5% 40%	2134
	21st to end	Day	20% 7% 3 5% 6% 3 4 4 5% 6% 36%	2238
May	1st to 10th	Day	19% 8% 3 6% 6% 3 5% 5% 6% 6% 34%	2340
	11th to 20th	Day	20% 7% 3 5% 5% 3 4 5% 5% 7% 37%	2301
	21st to end	Day	11% 5% 3 7% 6% 5% 6% 6% 7% 9% 37%	2673
June	1st to 10th	Day	11% 5% 2 5% 5% 3 4 5% 6% 9% 45%	2520
	11th to 20th	Day	9% 4 3 4 5% 3 5% 6% 6% 9% 47%	2520
	21st to end	Day	10% 4 3 6% 5% 3 5% 5% 7% 9% 43%	2520
July	1st to 10th	Day	10% 4 2 4 5% 3 5% 6% 7% 11% 41%	2520
	11th to 20th	Day	7% 4 2 5% 5% 4 6% 6% 7% 9% 45%	2520
	21st to end	Day	10% 4 2 5% 5% 3 6% 5% 7% 9% 45%	2743
August	1st to 10th	Day	9% 4 2 5% 5% 3 4 5% 6% 10% 47%	2304
	11th to 20th	Day	10% 5% 2 6% 5% 4 5% 5% 7% 9% 42%	2125
	21st to end	Day	6% 4 2 5% 5% 3 5% 5% 6% 9% 50%	2376
September	1st to 10th	Day	12% 5% 3 4 5% 3 5% 5% 5% 7% 46%	2160
	11th to 20th	Day	10% 4 2 4 5% 3 5% 6% 6% 8% 47%	2004
	21st to end	Day	11% 3 1 5% 5% 3 4 4 4 8% 52%	1980
October	1st to 10th	Day	13% 3 2 5% 5% 3 3 4 4 6% 51%	1980
	11th to 20th	Day	16% 5% 2 6% 5% 3 4 4 5% 6% 44%	1825
	21st to end	Day	21% 7% 3 6% 5% 3 4 4 4 5% 39%	1782
November	1st to 10th	Day	12% 5% 3 4 4 3 4 3 4 7% 52%	1672
	11th to 20th	Day	18% 8% 3 6% 5% 2 3 3 4 6% 42%	1710
	21st to end	Day	19% 9% 3 6% 4 3 5% 4 3 5% 39%	1710
December	1st to 10th	Day	19% 11% 4 8% 6% 3 4 4 4 5% 32%	1644
	11th to 20th	Day	17% 13% 7% 8% 5% 3 4 3 4 6% 31%	1918
	21st to end	Day	25% 17% 7% 8% 6% 3 4 4 4 4 18%	2783
January	1st to 10th	Night	17% 10% 5% 8% 6% 4 4 4 5% 6% 32%	2648
	11th to 20th	Night	18% 13% 5% 10% 6% 2 4 3 3 5% 29%	2660
	21st to end	Night	19% 12% 4 8% 5% 3 4 5% 4 6% 31%	2779
February	1st to 10th	Night	21% 11% 5% 9% 6% 3 4 4 4 5% 29%	2174
	11th to 20th	Night	16% 9% 4 8% 6% 3 4 4 4 6% 34%	2098
	21st to end	Night	21% 11% 4 6% 5% 2 3 4 5% 5% 34%	1776
March	1st to 10th	Night	17% 11% 3 5% 5% 3 3 4 4 5% 38%	2160
	11th to 20th	Night	19% 8% 3 5% 5% 3 4 4 4 7% 38%	2106
	21st to end	Night	22% 7% 3 7% 6% 3 4 4 5% 6% 33%	2012
April	1st to 10th	Night	14% 7% 3 6% 5% 3 5% 4 5% 7% 42%	1800
	11th to 20th	Night	17% 6% 4 5% 4 2 4 4 4 6% 44%	1775
	21st to end	Night	18% 7% 3 6% 6% 4 5% 5% 5% 5% 36%	1720
May	1st to 10th	Night	17% 8% 3 5% 5% 3 5% 4 5% 9% 36%	1620
	11th to 20th	Night	14% 5% 3 6% 5% 3 5% 4 4 8% 42%	1592
	21st to end	Night	9% 5% 2 6% 6% 3 6% 6% 7% 10% 41%	1600
June	1st to 10th	Night	10% 5% 3 4 4 4 4 4 4 8% 50%	1440
	11th to 20th	Night	8% 4 2 5% 5% 3 4 3 6% 8% 53%	1440
	21st to end	Night	7% 4 2 5% 4 3 4 5% 8% 11% 46%	1440
July	1st to 10th	Night	8% 3 2 5% 5% 3 5% 5% 6% 10% 49%	1440
	11th to 20th	Night	7% 3 2 5% 3 3 5% 4 6% 9% 53%	1440
	21st to end	Night	6% 4 3 4 4 3 3 3 4 10% 55%	1575
August	1st to 10th	Night	7% 4 2 4 5% 2 4 6% 5% 10% 50%	1627
	11th to 20th	Night	6% 4 2 5% 5% 3 5% 6% 6% 9% 50%	1776
	21st to end	Night	7% 4 2 3 3 3 4 4 6% 8% 57%	1980
September	1st to 10th	Night	12% 5% 2 5% 4 2 4 3 5% 7% 50%	1800
	11th to 20th	Night	7% 4 2 4 4 2 3 3 5% 7% 58%	1936
	21st to end	Night	12% 5% 2 4 4 2 3 3 5% 7% 50%	1980
October	1st to 10th	Night	9% 4 2 5% 4 2 4 4 5% 6% 56%	1980
	11th to 20th	Night	17% 6% 2 4 3 2 3 4 4 6% 49%	2129
	21st to end	Night	18% 8% 2 4 5% 3 4 4 5% 6% 40%	2574
November	1st to 10th	Night	12% 6% 2 5% 4 3 4 4 4 5% 52%	2406
	11th to 20th	Night	13% 8% 3 5% 5% 2 4 4 4 7% 44%	2470
	21st to end	Night	21% 9% 4 5% 5% 3 4 3 4 6% 37%	2470
December	1st to 10th	Night	18% 11% 5% 7% 6% 3 3 4 5% 5% 33%	2531
	11th to 20th	Night	18% 11% 4 7% 5% 3 3 4 4 5% 35%	3279
	21st to end	Night	27% 15% 5% 8% 6% 3 4 4 3 4 20%	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	57% 5% 8% 19% 11% 1	1518
	11th to 20th	Day	60% 4 12% 17% 7%	1520
	21st to end	Day	57% 4 12% 20% 6% 1	1719
February	1st to 10th	Day	56% 4 11% 19% 8% 2	1784
	11th to 20th	Day	54% 5% 11% 21% 8% 1	1758
	21st to end	Day	55% 5% 8% 21% 9% 2	1480
March	1st to 10th	Day	48% 5% 11% 24% 11% 1	1800
	11th to 20th	Day	50% 5% 12% 21% 11% 1	1854
	21st to end	Day	57% 5% 10% 21% 6% 1	2359
April	1st to 10th	Day	44% 6% 12% 22% 14% 1	2160
	11th to 20th	Day	45% 6% 9% 25% 11% 4	2134
	21st to end	Day	49% 5% 11% 21% 10% 3	2238
May	1st to 10th	Day	50% 7% 13% 20% 9%	2340
	11th to 20th	Day	47% 7% 12% 19% 14% 1	2305
	21st to end	Day	42% 10% 13% 20% 13% 2	2673
June	1st to 10th	Day	34% 8% 13% 26% 16% 3	2520
	11th to 20th	Day	31% 8% 14% 22% 21% 4	2520
	21st to end	Day	35% 9% 16% 20% 17% 4	2520
July	1st to 10th	Day	35% 9% 14% 24% 15% 3	2451
	11th to 20th	Day	31% 10% 14% 27% 16% 2	2445
	21st to end	Day	33% 8% 16% 25% 15% 2	2591
August	1st to 10th	Day	32% 8% 15% 28% 15% 2	2290
	11th to 20th	Day	35% 9% 14% 27% 13% 2	2125
	21st to end	Day	29% 7% 14% 26% 17% 7%	2376
September	1st to 10th	Day	37% 7% 11% 25% 17% 4	2160
	11th to 20th	Day	31% 9% 11% 25% 21% 3	2004
	21st to end	Day	31% 6% 10% 25% 25% 3	1980
October	1st to 10th	Day	34% 5% 11% 26% 21% 3	1980
	11th to 20th	Day	40% 5% 10% 22% 22% 1	1825
	21st to end	Day	48% 4 9% 25% 14% 1	1782
November	1st to 10th	Day	33% 4 13% 27% 16% 5%	1672
	11th to 20th	Day	45% 4 9% 23% 16% 4	1710
	21st to end	Day	49% 4 9% 22% 15% 1	1710
December	1st to 10th	Day	55% 5% 10% 19% 10% 1	1644
	11th to 20th	Day	56% 4 8% 25% 6% 1	1915
	21st to end	Day	70% 5% 10% 11% 5%	2783
January	1st to 10th	Night	53% 5% 9% 20% 12% 1	2648
	11th to 20th	Night	60% 3 11% 18% 7%	2660
	21st to end	Night	55% 4 11% 20% 9% 1	2779
February	1st to 10th	Night	58% 5% 13% 16% 7% 1	2174
	11th to 20th	Night	51% 4 11% 20% 11% 2	2099
	21st to end	Night	53% 4 10% 21% 10% 2	1776
March	1st to 10th	Night	49% 4 9% 23% 13% 2	2160
	11th to 20th	Night	47% 5% 12% 22% 13% 2	2106
	21st to end	Night	52% 5% 12% 21% 8% 2	2012
April	1st to 10th	Night	41% 6% 11% 26% 15% 2	1800
	11th to 20th	Night	41% 5% 10% 21% 18% 5%	1775
	21st to end	Night	47% 7% 10% 20% 13% 4	1720
May	1st to 10th	Night	46% 6% 12% 24% 11% 1	1620
	11th to 20th	Night	42% 7% 14% 20% 17% 1	1593
	21st to end	Night	36% 9% 14% 20% 15% 5%	1601
June	1st to 10th	Night	34% 6% 10% 25% 22% 4	1440
	11th to 20th	Night	31% 6% 11% 24% 22% 5%	1440
	21st to end	Night	29% 8% 17% 21% 20% 6%	1440
July	1st to 10th	Night	30% 10% 16% 21% 18% 5%	1400
	11th to 20th	Night	27% 5% 16% 28% 21% 3	1392
	21st to end	Night	27% 5% 15% 30% 20% 3	1487
August	1st to 10th	Night	29% 8% 15% 27% 18% 3	1617
	11th to 20th	Night	29% 8% 15% 27% 20% 3	1776
	21st to end	Night	25% 6% 14% 26% 22% 7%	1980
September	1st to 10th	Night	33% 6% 11% 26% 19% 6%	1800
	11th to 20th	Night	26% 4 11% 28% 26% 5%	1936
	21st to end	Night	32% 6% 10% 23% 24% 5%	1980
October	1st to 10th	Night	29% 6% 11% 25% 25% 4	1980
	11th to 20th	Night	36% 4 8% 25% 23% 4	2129
	21st to end	Night	45% 5% 9% 22% 17% 3	2574
November	1st to 10th	Night	35% 5% 9% 26% 21% 5%	2406
	11th to 20th	Night	40% 4 10% 24% 19% 3	2470
	21st to end	Night	50% 3 10% 23% 13% 1	2470
December	1st to 10th	Night	53% 5% 11% 19% 11% 1	2531
	11th to 20th	Night	52% 4 11% 20% 13%	3281
	21st to end	Night	69% 5% 8% 11% 6% 1	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	25% 19% 30% 18% 7% 1	270
	11th to 20th	Day	27% 14% 36% 18% 4	270
	21st to end	Day	24% 21% 33% 19% 4	282
February	1st to 10th	Day	30% 18% 33% 15% 5%	240
	11th to 20th	Day	27% 20% 33% 15% 5%	240
	21st to end	Day	30% 14% 39% 14% 3 1	198
March	1st to 10th	Day	21% 19% 40% 15% 5%	240
	11th to 20th	Day	29% 16% 33% 17% 5%	294
	21st to end	Day	28% 17% 31% 16% 7%	462
April	1st to 10th	Day	18% 16% 33% 24% 8% 1	420
	11th to 20th	Day	19% 17% 27% 23% 13% 2	412
	21st to end	Day	23% 15% 33% 18% 9% 2	420
May	1st to 10th	Day	21% 13% 30% 25% 10% 3	423
	11th to 20th	Day	19% 7% 28% 26% 15% 5%	447
	21st to end	Day	11% 4 28% 27% 21% 10%	627
June	1st to 10th	Day	11% 4 21% 33% 23% 7%	630
	11th to 20th	Day	10% 5% 22% 32% 23% 7%	630
	21st to end	Day	11% 5% 28% 27% 21% 8%	630
July	1st to 10th	Day	10% 3 13% 26% 26% 21%	621
	11th to 20th	Day	6% 3 17% 32% 29% 13%	618
	21st to end	Day	10% 2 14% 28% 33% 11%	684
August	1st to 10th	Day	10% 2 11% 28% 33% 17%	448
	11th to 20th	Day	15% 2 13% 31% 28% 11%	439
	21st to end	Day	5% 3 12% 31% 34% 16%	495
September	1st to 10th	Day	11% 4 15% 28% 31% 11%	450
	11th to 20th	Day	9% 2 11% 30% 29% 18%	450
	21st to end	Day	12% 7% 23% 23% 23% 13%	450
October	1st to 10th	Day	12% 4 26% 32% 19% 7%	450
	11th to 20th	Day	16% 15% 32% 22% 13% 2	302
	21st to end	Day	25% 19% 32% 19% 6%	297
November	1st to 10th	Day	13% 13% 34% 24% 14% 3	270
	11th to 20th	Day	21% 16% 30% 20% 10% 2	270
	21st to end	Day	21% 13% 34% 22% 9%	270
December	1st to 10th	Day	17% 21% 36% 18% 7% 2	270
	11th to 20th	Day	23% 13% 36% 20% 6% 1	270
	21st to end	Day	34% 14% 32% 14% 5%	297
January	1st to 10th	Night	22% 13% 33% 27% 5%	950
	11th to 20th	Night	26% 13% 35% 21% 4	950
	21st to end	Night	24% 13% 35% 25% 3	1025
February	1st to 10th	Night	26% 12% 35% 25% 2	734
	11th to 20th	Night	23% 14% 36% 24% 3	703
	21st to end	Night	27% 11% 37% 22% 3	592
March	1st to 10th	Night	22% 14% 35% 26% 4	720
	11th to 20th	Night	22% 12% 34% 26% 5%	720
	21st to end	Night	25% 7% 31% 30% 7%	626
April	1st to 10th	Night	16% 12% 32% 34% 6%	540
	11th to 20th	Night	20% 11% 27% 29% 12%	533
	21st to end	Night	20% 8% 35% 29% 7% 1	540
May	1st to 10th	Night	18% 7% 31% 34% 11%	540
	11th to 20th	Night	14% 5% 27% 35% 17% 2	531
	21st to end	Night	10% 3 21% 38% 25% 2	584
June	1st to 10th	Night	10% 4 19% 44% 23% 1	540
	11th to 20th	Night	10% 2 20% 44% 24% 1	540
	21st to end	Night	8% 1 21% 41% 27% 1	540
July	1st to 10th	Night	9% 2 11% 31% 40% 7%	525
	11th to 20th	Night	6% 3 13% 39% 35% 5%	522
	21st to end	Night	6% 2 13% 44% 33% 4	591
August	1st to 10th	Night	9% 2 8% 39% 39% 3	537
	11th to 20th	Night	7% 1 11% 40% 35% 5%	534
	21st to end	Night	9% 1 12% 32% 40% 5%	594
September	1st to 10th	Night	12% 3 14% 37% 30% 4	540
	11th to 20th	Night	8% 3 16% 34% 36% 4	676
	21st to end	Night	13% 6% 19% 33% 25% 4	720
October	1st to 10th	Night	9% 6% 22% 37% 21% 4	720
	11th to 20th	Night	19% 9% 28% 28% 14% 1	720
	21st to end	Night	23% 10% 32% 28% 7%	792
November	1st to 10th	Night	15% 7% 33% 32% 13%	740
	11th to 20th	Night	16% 12% 32% 30% 9%	760
	21st to end	Night	24% 10% 31% 27% 8%	760
December	1st to 10th	Night	23% 10% 37% 25% 5%	821
	11th to 20th	Night	25% 9% 33% 26% 7% 1	950
	21st to end	Night	30% 14% 30% 22% 3	1045

Page generated at 2024-01-24 09:37:32. Version ac07

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