Bonham State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Bonham State Park clear sky chart from 2005-11-05 to 2017-10-06.

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 TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(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

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
50%
15674
29%
47115
20%
15629
59%
15629
39%
25812

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 15thNight
36%
898
31%
2327
13%
895
48%
895
40%
1359
January16th to endNight
35%
960
34%
2496
12%
960
48%
960
40%
1445
February1st to 15thNight
32%
811
26%
2217
8%
807
43%
807
33%
1338
February16th to endNight
27%
593
31%
1855
10%
593
43%
593
32%
1030
March1st to 15thNight
33%
540
28%
1980
17%
540
48%
540
26%
1123
March16th to endNight
37%
576
24%
2112
17%
576
50%
576
28%
1187
April1st to 15thNight
32%
539
25%
1940
14%
539
49%
539
30%
1023
April16th to endNight
37%
540
25%
1743
18%
540
51%
540
35%
962
May1st to 15thNight
39%
540
24%
1620
14%
540
53%
540
33%
953
May16th to endNight
57%
563
26%
1684
23%
561
66%
561
40%
931
June1st to 15thNight
72%
540
25%
1620
25%
540
77%
540
52%
790
June16th to endNight
75%
540
27%
1620
28%
540
78%
540
49%
818
July1st to 15thNight
78%
510
23%
1530
26%
510
80%
510
45%
797
July16th to endNight
88%
564
30%
1594
37%
531
89%
531
56%
756
August1st to 15thNight
87%
539
37%
1610
43%
536
88%
536
59%
747
August16th to endNight
80%
573
28%
1844
33%
573
81%
573
38%
998
September1st to 15thNight
71%
540
25%
1980
29%
540
72%
540
35%
1025
September16th to endNight
75%
537
36%
1980
39%
537
79%
537
42%
940
October1st to 15thNight
61%
612
33%
1980
27%
612
65%
612
41%
1031
October16th to endNight
52%
704
37%
2112
22%
704
62%
704
47%
1058
November1st to 15thNight
52%
700
32%
2100
19%
700
62%
700
42%
1102
November16th to endNight
40%
895
32%
2335
16%
895
50%
895
39%
1374
December1st to 15thNight
37%
900
29%
2340
13%
900
47%
900
36%
1453
December16th to endNight
34%
960
27%
2496
12%
960
44%
960
34%
1572

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 ForecastData
Points
Cloud CoverDay
11%42442445%7%48%
48078
Night
9%423323347%55%
47313
TransparencyDay
34%39%23%21%6%
47778
Night
29%39%24%24%9%
47118
SeeingDay
11%417%29%27%9%
5684
Night
11%5%26%34%19%2
15676

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
13%5%24223235%54%
1611
16th to endDay
15%313223345%53%
1728
February1st to 15thDay
16%6%23412325%50%
1654
16th to endDay
17%5%23321235%50%
1619
March1st to 15thDay
19%5%23313245%46%
1980
16th to endDay
15%7%35%423335%44%
2110
April1st to 15thDay
12%41431445%6%49%
2007
16th to endDay
13%4245%2445%7%44%
2214
May1st to 15thDay
14%6%35%424445%43%
2331
16th to endDay
9%5%36%6%45%45%7%39%
2430
June1st to 15thDay
5%325%5%45%5%7%8%45%
2340
16th to endDay
6%324425%6%6%9%48%
2340
July1st to 15thDay
7%326%5%35%6%7%9%40%
2340
16th to endDay
43135%36%6%8%10%46%
2466
August1st to 15thDay
32145%245%7%8%55%
2340
16th to endDay
7%426%6%46%6%8%9%37%
2354
September1st to 15thDay
11%315%434448%47%
1980
16th to endDay
8%32432335%7%54%
1980
October1st to 15thDay
10%424423435%54%
1765
16th to endDay
9%31331222464%
1760
November1st to 15thDay
9%31333435%6%54%
1758
16th to endDay
12%5%2432222458%
1623
December1st to 15thDay
16%7%34313235%49%
1620
16th to endDay
17%6%33323335%48%
1728
January1st to 15thNight
11%423313245%56%
2327
16th to endNight
11%423213335%57%
2496
February1st to 15thNight
12%5%2431332454%
2209
16th to endNight
13%32331323456%
1855
March1st to 15thNight
15%5%24423345%48%
1980
16th to endNight
11%5%2442335%6%49%
2112
April1st to 15thNight
9%42442345%8%51%
1940
16th to endNight
10%424423446%53%
1743
May1st to 15thNight
9%425%42445%7%50%
1619
16th to endNight
5%413325%47%10%51%
1683
June1st to 15thNight
33322235%10%61%
1620
16th to endNight
221322445%10%60%
1620
July1st to 15thNight
42133245%7%13%50%
1620
16th to endNight
211132346%10%62%
1702
August1st to 15thNight
31132245%10%63%
1620
16th to endNight
3423435%6%7%11%47%
1844
September1st to 15thNight
9%42432336%6%54%
1980
16th to endNight
6%31332336%6%59%
1980
October1st to 15thNight
9%414313245%60%
1980
16th to endNight
9%31221213466%
2112
November1st to 15thNight
7%413323345%61%
2100
16th to endNight
12%413313345%55%
2335
December1st to 15thNight
15%5%2322343451%
2340
16th to endNight
15%6%23323445%49%
2496

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
33%25%21%29%6%
1612
16th to endDay
33%25%23%27%7%
1728
February1st to 15thDay
38%25%22%23%6%
1655
16th to endDay
37%26%22%21%9%
1619
March1st to 15thDay
40%28%20%21%7%
1980
16th to endDay
42%38%20%20%4
2112
April1st to 15thDay
34%49%24%18%8%
2007
16th to endDay
38%39%20%23%5%
2214
May1st to 15thDay
43%38%18%21%5%
2331
16th to endDay
41%411%22%17%1
2434
June1st to 15thDay
33%5%11%26%19%2
2340
16th to endDay
30%413%26%21%3
2340
July1st to 15thDay
34%6%14%30%13%
2201
16th to endDay
27%418%32%15%1
2311
August1st to 15thDay
24%414%30%23%2
2326
16th to endDay
37%6%15%26%10%3
2354
September1st to 15thDay
34%410%23%18%7%
1980
16th to endDay
28%38%24%26%8%
1980
October1st to 15thDay
33%29%20%19%14%
1765
16th to endDay
25%27%20%30%14%
1760
November1st to 15thDay
30%29%26%23%8%
1758
16th to endDay
32%1316%34%11%
1623
December1st to 15thDay
40%16%22%24%4
1620
16th to endDay
39%25%23%21%7%
1728
January1st to 15thNight
30%16%19%31%9%
2327
16th to endNight
29%26%21%29%10%
2496
February1st to 15thNight
34%26%21%23%11%
2219
16th to endNight
32%27%23%21%12%
1855
March1st to 15thNight
37%27%19%21%10%
1980
16th to endNight
35%310%21%23%5%
2112
April1st to 15thNight
31%39%23%18%13%
1940
16th to endNight
31%311%20%24%8%
1743
May1st to 15thNight
33%412%19%23%7%
1620
16th to endNight
27%417%27%17%4
1685
June1st to 15thNight
19%314%33%24%4
1620
16th to endNight
20%411%30%26%6%
1620
July1st to 15thNight
23%5%14%35%19%2
1530
16th to endNight
15%417%33%24%3
1594
August1st to 15thNight
16%212%34%27%6%
1610
16th to endNight
27%5%14%30%17%4
1844
September1st to 15thNight
29%310%23%22%10%
1980
16th to endNight
24%28%26%26%11%
1980
October1st to 15thNight
27%210%22%20%16%
1980
16th to endNight
23%1419%30%20%
2112
November1st to 15thNight
26%28%24%25%13%
2100
16th to endNight
31%26%17%30%12%
2335
December1st to 15thNight
35%28%22%22%8%
2340
16th to endNight
36%38%20%22%8%
2496

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
24%14%28%22%10%
90
16th to endDay
15%8%40%21%12%1
96
February1st to 15thDay
14%10%45%23%6%
90
16th to endDay
16%16%39%23%31
81
March1st to 15thDay
22%13%34%23%5%1
90
16th to endDay
10%12%36%27%11%2
96
April1st to 15thDay
12%8%29%37%11%
126
16th to endDay
20%10%33%22%10%2
324
May1st to 15thDay
16%9%33%27%10%2
468
16th to endDay
15%5%28%30%17%2
517
June1st to 15thDay
7%111%36%33%8%
495
16th to endDay
7%29%37%32%10%
495
July1st to 15thDay
6%16%36%38%9%
475
16th to endDay
4324%46%21%
515
August1st to 15thDay
5%231%45%14%
493
16th to endDay
11%1427%37%17%
394
September1st to 15thDay
2317%41%34%
135
16th to endDay
5%425%41%22%
135
October1st to 15thDay
4113%31%38%10%
107
16th to endDay
12%313%50%18%2
96
November1st to 15thDay
17%425%23%24%4
90
16th to endDay
22%16%33%20%43
90
December1st to 15thDay
25%6%31%23%13%
90
16th to endDay
16%19%38%20%4
96
January1st to 15thNight
14%9%35%32%7%
900
16th to endNight
13%8%38%31%7%
960
February1st to 15thNight
16%8%37%30%5%
811
16th to endNight
17%11%42%26%3
593
March1st to 15thNight
17%8%35%30%7%
540
16th to endNight
13%9%35%32%8%
576
April1st to 15thNight
11%9%42%29%7%
539
16th to endNight
13%5%37%32%9%1
540
May1st to 15thNight
12%6%36%31%12%1
540
16th to endNight
6%326%40%20%2
563
June1st to 15thNight
5%114%44%30%3
540
16th to endNight
4113%42%34%4
540
July1st to 15thNight
5%17%44%36%5%
510
16th to endNight
2334%49%8%
564
August1st to 15thNight
3236%48%8%
539
16th to endNight
5%338%44%7%
573
September1st to 15thNight
11%16%35%42%3
540
16th to endNight
7%8%38%37%6%
537
October1st to 15thNight
11%220%37%25%3
612
16th to endNight
11%429%33%18%2
704
November1st to 15thNight
8%6%28%38%17%1
700
16th to endNight
15%8%32%29%13%
895
December1st to 15thNight
18%7%32%34%7%
900
16th to endNight
19%7%34%30%7%
960
Page generated at 2017-10-07 13:07:50. Version ac04

Copyright 2017 A. Danko


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