該(gai)保護(hu)區(qu)地(di)(di)理位置(zhi)為(wei):東(dong)經126°35′~128°02′,北緯42°06′~43°51′。總(zong)面(mian)(mian)(mian)(mian)積(ji)約114.5萬公頃。其(qi)中林地(di)(di)82.3萬公頃,占總(zong)面(mian)(mian)(mian)(mian)積(ji)71.9%;水域(yu)5.7萬公頃,占總(zong)面(mian)(mian)(mian)(mian)積(ji)的(de)5.0%。三湖保護(hu)區(qu)地(di)(di)處長(chang)白山(shan)(shan)余脈(mo)(mo)。四面(mian)(mian)(mian)(mian)環山(shan)(shan),西面(mian)(mian)(mian)(mian)是吉林哈達(da)嶺(ling)(ling)山(shan)(shan)脈(mo)(mo),北面(mian)(mian)(mian)(mian)是老爺嶺(ling)(ling)山(shan)(shan)脈(mo)(mo),東(dong)面(mian)(mian)(mian)(mian)是威虎嶺(ling)(ling)和黃(huang)泥嶺(ling)(ling)山(shan)(shan)脈(mo)(mo),南面(mian)(mian)(mian)(mian)是老嶺(ling)(ling)山(shan)(shan)脈(mo)(mo)。地(di)(di)勢東(dong)南高(gao)西北低。地(di)(di)貌(mao)多(duo)為(wei)中(高(gao))山(shan)(shan)?低(丘)山(shan)(shan)?崗(gang)(臺)川類。其(qi)面(mian)(mian)(mian)(mian)積(ji)比例大(da)致為(wei)七山(shan)(shan)二崗(gang)一川。境內(nei)山(shan)(shan)巒起伏,綿延不斷,溝壑縱(zong)橫(heng),異(yi)峰突兀。海(hai)拔(ba)(ba)800米以上的(de)山(shan)(shan)峰有80余座,其(qi)最(zui)高(gao)為(wei)南樓山(shan)(shan),海(hai)拔(ba)(ba)1404.8米,在樺甸(dian)市常(chang)山(shan)(shan)境內(nei);最(zui)低為(wei)豐滿壩下,海(hai)拔(ba)(ba)約190米。該(gai)地(di)(di)區(qu)地(di)(di)質構成多(duo)為(wei)玄武巖(yan)、石灰巖(yan)、土(tu)壤類型(xing)為(wei)暗(an)棕壤、白漿土(tu)、草甸(dian)土(tu)、棕色(se)森(sen)林土(tu)、泥炭土(tu)等。
三湖保護區處于北(bei)溫(wen)(wen)帶大(da)陸(lu)性季(ji)風(feng)氣(qi)候區內(nei)。四季(ji)分明,年(nian)、日較差大(da)。春季(ji)干燥(zao)多風(feng)?夏季(ji)溫(wen)(wen)熱(re)多雨?秋季(ji)晴(qing)爽?冬季(ji)嚴寒?年(nian)平均氣(qi)溫(wen)(wen)在1.9℃~4.4℃之間(jian)?極(ji)端高溫(wen)(wen)36.6℃,極(ji)端低溫(wen)(wen)-45℃。年(nian)≥10℃積溫(wen)(wen)為(wei)1900℃~2800℃,并呈由南(nan)至北(bei)增加趨勢?年(nian)日照時(shi)數2350~2450小時(shi)?年(nian)降水量由南(nan)向北(bei)略有減(jian)少,為(wei)834~673毫米之間(jian)。無(wu)霜期大(da)致為(wei)110~130天。一月平均氣(qi)溫(wen)(wen)約為(wei)-18℃,七月平均氣(qi)溫(wen)(wen)約為(wei)20℃左右。該區夏季(ji)盛行西南(nan)風(feng),冬季(ji)盛行西北(bei)風(feng)。
保(bao)護(hu)區由于受到三(san)個(ge)湖(hu)泊及(ji)森(sen)(sen)林等因(yin)素影響,又具有湖(hu)泊氣候(hou)、谷(gu)地氣候(hou)和森(sen)(sen)林氣候(hou)的復合特征。