I will also be participating in Reitaisai.
The work I'll be presenting this time is below.
Biggest nitpick, I'd translate the pronouns in the opening paragraphs as "we", since he's speaking formally on behalf of his circle, not his own person

. He's also using the full name of Reitaisai here, which I tend to translate more properly as "Hakurei Shrine Regular Grand Festival" when possible.
The further translations I'm sure you all want!
Tanned Cirno's description:
灼熱の太陽が降り注ぐ、情熱的で熱気溢れる季節。
うだるような暑さと、全てを洗い流す夕立など
最も表情豊かな季節である。
The season of being poured upon by a scorching sun,
brimming with a zesty haze.
Bathed sometimes in seething heat, sometimes in evening showers,
this is the season with a most expressive face.
The normal difficulty is 夏の夕立級 "Summer Evening Shower Class".
The difficult word this time is 璋. Pronounced
zhāng in mandarin Chinese, it is one of several types of ritual objects made with jade in ancient China - I'm talking about 4500BC to 200BC ancient.
You can see six of the most common such objects on
this page.
Zhang is the second-to-last one, resembling a bladed weapon in shape. Among the six objects,
zhang stands for the south and summer.
Here's an English version of the same info.
Both
zhang and
gui were probably used somewhat like scepters carried by courtiers in those ancient courts. While the associated rituals had long faded from the lives of the Chinese people, the words
zhang and
gui remained as symbols of moral uptightness, and are often used in people's names.
So if both
zhang and Miko's
shaku are ancient Chinese artifacts translated as "scepters", and their shapes are also similar, what is the difference? Well, the
shaku was originally a less august object made with not-so-precious materials, used by courtiers to write down their memos on, but eventually turned into scepters of the Japanese court (you can still see the emperors and high priests of modern Japan holding them in ceremonies), while
zhang has not seen use in more than two thousand years.
I hope this somewhat clears up things!
Trivia:
Probably not relevant to Touhou,
zhang is also a symbol of giving birth to boys in old China:
Sons shall be born to him:
They will be put to sleep on couches;
They will be clothed in robes;
They will have zhang to play with;
Their cry will be loud.
They will be [hereafter] resplendent with red knee-covers,
The [future] king, the princes of the land.
Daughters shall be born to him:
They will be put to sleep on the ground;
They will be clothed with wrappers;
They will have ceramic [spinning wheels] to play with.
It will be theirs neither to do wrong nor to do good.
Only about the spirits and the food will they have to think,
And to cause no sorrow to their parents.
(Based on
this translation)
Addenum:
Zhang can also be another ancient Chinese artifact: the handle of a jade ladle, used to pour a sacrificial wine on the ground. However these things are all too old for us to know how exactly they were used. For all we know, the handle and the scepter may be one and the same.
Itsuari further suggests this can potentially connect the story to a currently ongoing plot thread in Touhou: the Gensokyoan mythology of the Big Dipper as the ultimate youkai - a heavenly dragon, threatening to swallow the light of Polaris.